Recommended resource available free online - Dr John Piper's entire book (Pdf) - A Hunger for God - Desiring God Through Fasting and Prayer

Whenever - Notice Jesus does not say "if" you fast but "when" you fast. The implication is not subtle is it?  Have you ever fasted? Jesus takes for granted that his disciples will observe the custom of fasting. Clearly, Jesus assumed that fasting was good and that it would be done by His disciples. Jesus mentioned this discipline later in Matthew 9:15 declaring

The days will come when the bridegroom is taken away from them, and then they will fast.”

So Jesus is not teaching on whether we should fast or not. He is assuming we will fast and teaching us how to do it and, especially, how not to do it.  

Dietrich Bonhoeffer wrote that...

Jesus takes it for granted that his disciples will observe the pious custom of fasting. Strict exercise of self-control is an essential feature of the Christian’s life. Such customs have only one purpose—to make the disciples more ready and cheerful to accomplish those things which God would have done...When the flesh is satisfied it is hard to pray with cheerful­ness or to devote oneself to a life of service which calls for much self-renunciation... We have to practice strictest daily discipline; only so can the flesh learn the painful lesson that it has no rights of its own. (The Cost of Discipleship)

J C Ryle explains that...

Fasting, or occasional abstinence from food in order to bring the body into subjection to the spirit, is a practice frequently mentioned in the Bible, generally in connection with prayer. David fasted when his child was sick (2 Samuel 12:16); Daniel fasted when he sought special light from God (Daniel 9:3); Paul and Barnabas fasted when they appointed elders (Acts 14:23); Esther fasted before going in to Ahasuerus (Esther 4:16). It is a subject about which we find no direct command in the New Testament. It seems to be left to everyone’s discretion, whether he will fast or not. In this absence of direct command we may see great wisdom. Many a poor man never has enough to eat, and it would be an insult to tell him to fast: many sick people can hardly be kept well with the closest attention to diet, and could not fast without bringing on illness. It is a matter in which each person must be persuaded in their own mind, and not rashly condemn others who do not agree. One thing only must never be forgotten: those who fast should do it quietly, secretly and without ostentation. Let them not “show men they are fasting.” Let them not fast to man, but to God.

C H Spurgeon's comments...

Having dealt with prayer, our King now instructs us as to fasting. Fasting took a leading place in devotion under the Law, and it might profitably be more practiced even now under the Gospel. The Puritans called it “soul-fattening fasting”, and so many have found it. We must, by order of our King, avoid all attempt at display in connection with this form of devotion. Hypocrites went about with faces unwashed, and dolorous, that all might say, “See how rigidly those men are fasting. What good men the, must be!” To look miserable in order to be thought holy- is a wretched piece of hypocrisy; and as it makes fasting into a trick to catch human admiration, it thereby destroys it as a means of grace. We cannot expect to get a reward both from the praise of our fellows and the pleasure of God.

We have our choice; and if we snatch at the minor reward, we love the major. May it never be said of us, “They have their reward. ” (Commentary)

Fast (3522) (nesteuo  from ne- = not + esthío = to eat) means to abstain from food. Fasting consisted of abstinence from food to express dependence on God and submission to His will.

Fasting is a valid discipline and one which Jesus did not annul. The only fast God commanded was once per year on the Day of Atonement. The Jewish religious teachers had added two fasts to be performed each Monday and Thursday, a practice which was observed ritualistically by the "pious" Pharisees.

Phil Newton writes that...

Fasting has been practiced by many different religions for centuries. It is personal self-discipline in which a person denies himself a normal need in order to learn to restrain his passions and desires, and to express his devotion. Often God’s people have fasted in order to express humility before the Lord, and to show an earnest desire for the Lord to work in a particular way. Most commonly, fasting involves denying oneself a meal or meals in order to give oneself to the purpose of seeking God’s face. But fasting is never to be used for drawing attention to one’s spirituality or devotion... The gloomy, sullen looks on their faces give the pretentious fasters a ready audience. The language suggests an almost unrecognizable look, as they leave their hair disheveled, neglect bathing, and maybe even accentuate a strange pallor to the skin.

In our day it seems the most common thing is for people to announce that they are fasting or to tell about their fast. I received a booklet from a Baptist pastor several years ago telling about his 40-day fast, and how that became the key to his spiritual growth and his church’s growth. Then he outlined in true-Baptist program fashion how to institute such a fast in one’s own life. But Jesus tells us... Let this be between you and the Lord. The Lord sees in secret and rewards accordingly.  (Sermon)

What principles for fasting are given in Matthew 6:16-18? Don't fast like a hypocrite, putting on a gloomy face to impress men - that's your entire reward! When you fast take care of your appearance so men don't know you are fasting - then your Father will repay you. Notice that Jesus says "when you fast" not "if you fast" indicating it is expected by our Lord. However, He does not command fasting. Thus fasting is a choice we each must make. It is a voluntary spiritual discipline.

Fasting is a Christian’s voluntary, non-coerced abstinence from food or water for spiritual purposes. 

Fasting by a non-Christian has no eternal value since the discipline’s motives and purposes are to be God-centered.

Fasting runs counter to America's self-indulgent, "me, my, mine" mindset,  and thus it is not surprising that many Christians have not given serious consideration to the discipline of fasting. The act of fasting directly opposes the desires of our fallen flesh, which are continually appealed to by the world and the tempter. Of course, there are some people who cannot and should not fast because of medical reasons. However, for the majority of Christians, it be prudent to consider engaging in the practice of fasting, as saints have done throughout the Old Testament and in the early church (cf Acts 13:2-3, 14:23).

Fasting is not to impress God and earn His acceptance, our acceptance having been made full and complete on the basis of the finished work of the Lord Jesus Christ. Fasting does not earn God’s favor! Like alms and prayer, fasting is to be done as an act of devotion to God and not to win the approval of anyone else.

Fasting, as with the spiritual disciplines of giving and praying, is directed toward our Father and is not done for the adulation of men. When we fast, we must not do anything that will draw attention to our appearance, our hungry state or our dedication to God. Fasting is between the saint and his God.

Fasting is mentioned in Scripture more than several other important doctrines including such teachings as baptism (about 77 times for fasting, 75 for baptism). Most believers have been baptized but how many have fasted?

Fasting in Scripture is almost always associated with prayer. Some feel that fasting helps one focus our prayers of intercession and supplication. We should not however assume that fasting is like a "spiritual hunger strike" that in any way compels or manipulates God. Clearly, if we petition for something out of God’s will, fasting does not incline Him produce an affirmative response. In short, fasting does not change God’s hearing so much as it changes our praying.

Fasting for God's guidance is clearly seen in Scripture (see Judges 20, Acts 14:23), but fasting does not ensure certainty that we will receive clear guidance. On the other hand, fasting rightly motivated does make us more receptive to our Father Who seeks to guide us.

Fasting is often a manifestation of grief or mourning, as when King Saul was killed by the Philistines resulting in the men of Jabesh Gilead fasting seven days (cf 1Sa 31:13)

Martyn Lloyd-Jones wrote that...

Fasting, if we conceive of it truly, must not...be confined to the question of food and drink; fasting should really be made to include abstinence from anything which is legiti­mate in and of itself for the sake of some special spiritual purpose. There are many bodily functions which are right and normal and perfectly legitimate, but which for special peculiar reasons in certain circumstances should be con-trolled. That is fasting. (Lloyd-Jones, D. M.  Studies in the Sermon on the Mount)

David R Smith adds that...

A selfish person is unable to enjoy the gospel; a Christian is someone who has begun to deny himself, and is in the con­tinuous process of denying himself. Jesus said “If any man will come after Me, let him deny himself, and take up his cross, and follow Me.” Self-denial is not limited to one par­ticular kind of giving; it embraces all personal disciplines. Fasting is only one discipline; nevertheless, it is self-denial. This does not mean that to fast is to embrace legalism; it is gospel liberty which encourages us to deny ourselves...

Nobody can maintain a desired state of mind whilst his bodily condition is not in accordance with it. If a man is anxious to devote himself to spiritual things, for a time, he is obliged to ensure that his body is in similar environment, or else he may not succeed. He cannot be reverent in the midst of his own physical irreverence. Fasting ensures the correct environment for sorrowful and serious considerations. Asterius wrote, in the 4th Century, that one role of fasting is to ensure that the stomach does not make the body boil like a kettle, to the hindering of the soul...

Fasting does not create faith, for faith grows in us as we hear, and read, and dwell upon, God’s Word; it is a work of the Holy Spirit to bring faith to God’s people. However, fasting has the capacity to encourage faith in the one who is involved in this discipline. It seems as though the neglect of self feeds the faith which God has implanted in the hearts of born-again believers. This doesn’t mean that those who eat the least have the most faith; such a view is not only untrue, it is extremist. It is simply that regular self-denial has its ben­efits, and one of these is seen in a personal increase in faith. (Fasting: A Neglected Discipline. Christian Literature Crusade, 1954)

Fasting in the Old Testament was commonly associated with seeking of God's deliverance and/or protection (cf 2Chronicles 30:3-4, Ezra 8:21-23).  Queen Esther called for a "cooperative fast" from the Jews of Susa as she prepared for an uninvited and therefore potentially dangerous entrance into the presence of King Xerxes. In this hour of great need, Queen Esther requested Mordecai to...

Go, assemble all the Jews who are found in Susa, and fast for me; do not eat or drink for three days, night or day. I and my maidens also will fast in the same way. And thus I will go in to the king, which is not according to the law; and if I perish, I perish. So Mordecai went away and did just as Esther had commanded him. (Esther 4:16-17)

Fasting can be associated with confession and repentance. In 1 Samuel 7 we read a study of national revival (read the entire chapter) in which God raised up Samuel, who called the people to repentance, confession, and cleansing. Intercession was made through the blood of a lamb, and there was victory over the Philistines.  Fasting was a component of this "revival"...

And they (the Israelites) gathered to Mizpah, and drew water and poured it out before the LORD (this was a sacrificial act in the arid land of Israel, symbolic of their repentant hearts as described in 1Sa 7:3-4 where Samuel called them to return to the LORD and they responded by removing their idols and serving Jehovah), and fasted on that day, and said there, "We have sinned against the LORD." And Samuel judged the sons of Israel at Mizpah. (1Samuel 7:6)

The prophet Joel in light of impending judgment (The Day of the Lord) asked "Who can endure it?" and then provided the "way of escape"...

"Yet even now," declares the LORD, "Return to Me with all your heart, and with fasting, weeping, and mourning; and rend your heart and not your garments." Now return to the LORD your God, for He is gracious and compassionate, slow to anger, abounding in lovingkindness, and relenting of evil. (Joel 2:12-13)

Here God Himself associates fasting with a changed change (repentance) and a return to Him. This passage also warns that fasting without a changed heart is a meaningless dead work. Beloved, is God calling you to deal with a specific sin in your hardened heart, so that you might return to Him in brokenness and repentance with fasting, weeping and mourning?  Jesus promised that blessed are those mourn over their sins for they shall be comforted (see Matthew 5:4) Don't try to substitute a spiritual discipline such as fasting, for God' clear call to confess and forsake that sin which so easily entangles you (cf Proverbs 28:13). It is a perversion of fasting from food or drink when we refuse God's "chosen fast" (cf Isaiah 58:3-12, especially verses 6-7) to cease feeding a sin we want to continue feeding.

Fasting, rightly motivated, is a physical expression of humility before God, just as kneeling or prostrating yourself in prayer can reflect humility before Him. For example first Kings records that one of the most wicked men in Israel's history, King Ahab, eventually humbled himself before God and demonstrated it by fasting...

And it came about when Ahab heard these words, that he tore his clothes and put on sackcloth and fasted, and he lay in sackcloth and went about despondently. Then the word of the LORD came to Elijah the Tishbite, saying, "Do you see how Ahab has humbled himself before Me? Because he has humbled himself before Me, I will not bring the evil in his days, but I will bring the evil upon his house in his son's days." (1Kings 21:27-29)

David, a man after God's Own heart, illustrates the relationship between prayer, fasting and humility recording that...

as for me, when they (David's enemies!) were sick, my clothing was sackcloth; I humbled my soul with fasting; and my prayer kept returning to my bosom. (Psalm 35:13)

Fasting is not always associated with humility,  as illustrated by the self-righteous Pharisee who boasted...

'I fast twice a week; I pay tithes of all that I get.' (Luke 18:12)

The Jews of Jesus' day had a teaching that Moses went up on Mount Sinai to receive the Law on a Thursday, and returned with it on a Monday. Consequently, the Pharisees considered fasting on those two days was considered a special mark of holiness.

Fasting can be the work of God in a place that has experienced tragedy, disappointment, or apparent defeat as seen with Nehemiah when he heard that despite the return of many Jewish exiles to Jerusalem, the city still had no wall...

Now it came about when I heard these words, I sat down and wept and mourned for days; and I was fasting and praying before the God of heaven. (Nehemiah 1:4)

Nehemiah  had a deep sense of Jerusalem’s significance to God and was greatly distressed that affairs there had not advanced the cause and glory of God. Note that Nehemiah's focus was toward the God of heaven and for the glory of God. When I fast is that my focus and my goal?

Fasting can be an act of sheer devotion to God as we see with the godly prophetess Anna, Luke recording that...

there was a prophetess, Anna the daughter of Phanuel, of the tribe of Asher. She was advanced in years, having lived with a husband seven years after her marriage, and then as a widow to the age of eighty-four. And she never left the temple, serving night and day with fastings and prayers. (Luke 2:36-37)

Anna is one of those people that I cannot wait to meet. Luke gives details of her life which suggest that for well over half a century she was at the Temple serving God with “fastings and prayers.” Clearly for Anna, her fasting as an incredible expression of worship to her Lord. Here we see fasting can be an expression of finding one's greatest pleasure and enjoyment in God. 

May you and I dear reader yearn for times when God causes us like Anna to crave the spiritual banquet of His presence more than any physical, temporal and earthly meal. Remember that Jesus promises that our Father in heaven will reward us when He sees a rightly motivated, pure in heart fast for His eyes only.

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There are a number of books available on this discipline but many are less than spiritually sound and border on the mystical. In his Preface to A Hunger for God  (I highly recommend this excellent resource which is generously made available at no charge online) Dr John Piper gives believers wise counsel regarding the spiritual discipline of fasting writing...

Beware of books on fasting. The Bible is very careful to warn us about people who “advocate abstaining from foods, which God created to be gratefully shared in by those who believe and know the truth” (1 Timothy 4:1-3). The apostle Paul asks with dismay, “Why .. . do you submit yourself to decrees, such as ‘Do not han­dle, do not taste, do not touch’?” (Colossians 2:20-21). He is jealous for the full enjoyment of Christian liberty. Like a great declaration of freedom over every book on fasting flies the ban­ner, “Food will not commend us to God; we are neither the worse if we do not eat, nor the better if we do eat” (1 Corinthians 8:8). There once were two men. One said, “I fast twice a week”; the other said, “God be merciful to me a sinner.” Only one went down to his house justified (Luke 18:12-14).

The discipline of self-denial is fraught with dangers— perhaps only surpassed by the dangers of indulgence. These also we are warned about: “All things are lawful for me, but I will not be mastered by anything” (1 Corinthians 6:12). What masters us has become our god; and Paul warns us about those “whose god is their appetite” (see note Philippians 3:19). Appetite dictates the direc­tion of their lives. The stomach is sovereign. This has a religious expression and an irreligious one. Religiously “persons . . . turn the grace of our God into licentiousness” (Jude 4) and tout the slogan, “Food is for the stomach and the stomach is for food” (1 Corinthians 6:13). Irreligiously, with no pretext of pardoning grace, persons simply yield to “the desires for other things [that] enter in and choke the word” (Mark 4:19).

“Desires for other things”—there’s the enemy. And the only weapon that will triumph is a deeper hunger for God. The weak­ness of our hunger for God is not because he is unsavory, but because we keep ourselves stuffed with “other things.” Perhaps, then, the denial of our stomach’s appetite for food might express, or even increase, our soul’s appetite for God. (Piper, John. available in Pdf online - A Hunger for God)

DO NOT PUT ON A GLOOMY FACE AS THE HYPOCRITES DO, FOR THEY NEGLECT THEIR APPEARANCE SO THAT THEY WILL BE NOTICED BY MEN WHEN THEY ARE FASTING: me ginesthe (2PPMM) hos hoi hupokritai skuthropoi, aphanizousin (3PPAI) gar ta prosopa auton hopos phanosin (3PAPS) tois anthropois nesteuontes; (PAPMPN)  (Mt 6:2,5; 1Kings 21:27; Isaiah 58:3, 4, 5; Zechariah 7:3, 4, 5; Malachi 3:14; Mark 2:18; Luke 18:12)

Do not put on a gloomy face - Young's rendering is more literal "be ye not as the hypocrites, of sour countenances". The present imperative is a command that is coupled with a negative particle (Greek = "me") which calls for them to stop this practice.

Gloomy (4659) (skuthropos from skuthros = sullen, grim + ops = countenance) means to look sad, somber, downcast or gloomy.

Spurgeon writes that...

I heard persons speak of certain emaciated ecclesiastics as being such wonderfully holy men. “How they must have fasted! They look like it. You can see it in their faces.” Probably produced by a fault in their digestion much more likely, than by anything else and if not — if we are to suppose that the spareness of a man a person is to be the token of his holiness — then the living skeleton was a saint to perfection. But we are not beguiled by such follies as these. The Christian man fasts but he takes care that no one shall know it. He wears no ring or token even when his heart is heavy. Full often he puts on a cheerful air, lest by any means he should communicate unnecessary sorrow to others, and he will be cheerful and happy, apparently, in the midst of company, to prevent their being sad, for it is enough for him to be sad himself, and sad before his Father’s face.

---

 Do not imagine that the appearance of sadness indicates sanctity—it often means hypocrisy. To conceal one’s own griefs for the sake of cheering others implies a self-denying sympathy which is the highest kind of Christianity.

Noticed by men - This is the reward the hypocrites desire. If we are honest, we will all agree that it is in a sense "rewarding" when others compliment us on our  spiritual discipline, zeal, or devotion?

How you fast depends on whom you want to impress. If your fast is for your spiritual benefit and God’s glory, no one else needs to applaud your commitment.

Harry Ironside reminds us that our Lord Jesus...

was guileless in all His ways, and He calls for absolute honesty in the behavior of His disciples. Let him who is abstaining from food or other things in order to have more time with God, cultivate a cheerful manner as becomes one who enjoys communion with the Father.

Piper adds that...

Few things feel more gratifying to the heart of fallen man than being made much of for our accomplishments, especially our moral and religious accomplishments... All of this we are prone to do because of our seemingly insatiable appetite for the praise of men. We want to be made much of. We want people to like us and admire us and speak well of us. It is a deadly drive. Jesus warned us, “Whoever exalts himself shall be humbled; and whoever hum­bles himself shall be exalted” (Matthew 23:12). (Ibid)

TRULY I SAY TO YOU, THEY HAVE THEIR REWARD IN FULL: amen lego (1SPAI) humin apechousin (3PPAI) ton misthon auton

Reward in full - Jesus is saying that  that if you love to be "rewarded" with praise and admiration from people, you will receive that "reward" but nothing more.

The following Topical summary is modified from Torrey's Topical Textbook (See also ISBE article on fasting)

Spirit of, explained- Isaiah 58:6,7
Not to be made a subject of display -Matthew 6:16, 17, 18
Should be to God -Zechariah 7:5; Matthew 6:18
For the chastening of the soul -Psalms 69:10
For the humbling of the soul -Psalms 35:13
 

OBSERVED ON OCCASIONS OF

Judgments of God-Joel 1:14; Joel 2:12-13
Public calamities -2 Samuel 1:12
Afflictions of the Church -Luke 5:33-35
Afflictions of others -Psalms 35:13; Daniel 6:18
Private afflictions - David over illness of infant son by Bathsheba 2Samuel 12:16
Desire for God's protection-Ezra 8:21
Approaching danger- Esther 4:16
Approaching judgment of God-Jonah 3:5-8
Sorrow of Hannah over her barrenness 1Samuel 1:6-8
Death of friends or enemies David -Saul & Jonathan died 2Sa 1:12
Desire to serve God -Anna serving w/ fasting & prayers Lk 2:37
Ordination of ministers-seeking wisdom & guidance -Acts 13:3; 14:23
 

ACCOMPANIED BY

Prayer-Ezra 8:23; Daniel 9:3
Confession of sin -1Samuel 7:6; Nehemiah 9:1,2
Mourning -Joel 2:12
Humiliation -Deuteronomy 9:18; Nehemiah 9:1

Promises connected with -Isaiah 58:8, 9, 10, 11, 12; Matthew 6:18

OF HYPOCRITES

Described -Isaiah 58:4,5
Ostentatious -Matthew 6:16
Boasted of, before God -Luke 18:12
Rejected -Isaiah 58:3; Jeremiah 14:12
 

Extraordinary Exemplified

Our Lord -Matthew 4:2
Moses-Exodus 34:28; Deuteronomy 9:9,18
Elijah -1Kings 19:8
 

National Exemplified

Israel -Judges 20:26; Ezra 8:21; Esther 4:3,16; Jeremiah 36:9
Men of Jabesh-gilead-1 Samuel 31:13
Ninevites -Jonah 3:56, 7, 8
 

Of Saints Exemplified

David -2 Samuel 12:16; Psalms 109:24
Nehemiah -Nehemiah 1:4
Esther -Esther 4:16
Daniel -Daniel 9:3
Disciples of John -Matthew 9:14
Anna -Luke 2:37
Cornelius -Acts 10:30
Christians -Acts 13:2
Apostles -2Corinthians 6:5
Paul -2Corinthians 11:27
 

Of the wicked-Exemplified

Elders of Jezreel -1Kings 21:12
Ahab -1Kings 21:27
Pharisees -Mark 2:18; Luke 18:12

The sacrifice of the personal will, which gives to fasting all its value, is expressed in the old term used in the law, afflicting the soul . Fasting is usually born out of a need (approaching danger, approaching judgment, death of someone, ordination of ministers) as shown especially in the occasions mentioned above.

Fasting can be sincere and for proper reasons. It can also be done for selfish purposes. The first is pleasing to God, the latter isn't. In Zechariah 7:5, God asks His people the question,

"When you fasted and mourned in the fifth and seventh months these seventy years, was it actually for Me that you fasted?" (Zechariah 7:5)

The question one must always ask when fasting deals with our motive for fasting

Are you seeking God or seeking to manipulate God?

Fasting calls us from the preoccupations of body and soul in the day-by-day pressures of life. It summons us into such serious communion with our Lord that we voluntarily abstain from our normal absorption with such needs as food and drink.

As an expression of lamentation and/or penitence, fasting nearly always is associated with weeping (Judges 20:26; Esther 4:3; Psalm 69:10; Joel 2:12), confession (1 Sam 7:6; Dan 9:3), and the wearing of sackcloth (1 Kings 21:27; Neh 9:1; Esther 4:3; Psalm 69:10; Dan 9:3).

Fasting was frequently associated with supplication (prayer). David prayed and fasted over his sick child (2 Sam 12:16), weeping before the Lord in earnest intercession (vv. 21-22). Nehemiah, having heard of Jerusalem's desolation, wept, fasted, and prayed that God would give him favor with King Artaxerxes of Persia so that he might return to his homeland and repair its ruins (Neh 1:4-11). Esther, under similar circumstances, urged Mordecai and the Jews to fast for her as she planned to appear before her husband the king (Esther 4:16). Clearly, fasting and petition are here one and the same (cf. Jer 14:12).

It is interesting that the purpose of fasting is never explicitly stated in Scripture. From the Scriptural examples connecting fasting to penitence, mourning, and supplication it appears that fasting is a means of self-denial that opens one to God. Fasting is a spiritual practice in which believers are given the opportunity to express themselves in an undivided and intensive devotion to the Lord.

There are several types of fasts

1) Partial: as seen in Daniel 10:2,3

2) Total: as seen with our Lord's 40 day fast in the wilderness Matthew 4:2

3) Absolute (no food or water): for 3 days in Esther 4:16

4) Voluntary: Daniel 9:3

5) Involuntary: because of grief or no desire Daniel 6:18 or no food available 2 Cor 6:5

The sole fast required by the law of Moses was that of the great Day of Atonement, Leviticus 23:26-32. It is called "the fast" (Acts 27:9).

The only other mention of a periodical fast in the Old Testament is in Zechariah 7:1-7; 8:19, from which it appears that during their captivity the Jews observed four annual fasts. (Ed note: But these were not prescribed by God)

The fast of the fourth month, kept on the seventeenth day of Tammuz, the anniversary of the capture of Jerusalem by the Chaldeans; to commemorate also the incident recorded Exodus 32:19. (Compare Jeremiah 52:6,7)

The fast of the fifth month, kept on the ninth of Ab (Compare Numbers 14:27), to commemorate the burning of the city and temple (Jeremiah 52:12,13).

The fast of the seventh month, kept on the third of Tisri (Compare 2 Kings 25), the anniversary of the murder of Gedaliah (Jeremiah 41:1,2).

The fast of the tenth month (Compare Jeremiah 52:4; Ezekiel 33:21; 2KIngs 25:1), to commemorate the beginning of the siege of the holy city by Nebuchadnezzar.

There was in addition to these the fast appointed by (Esther 4:16).

Public national fasts on account of sin or to supplicate divine favour were sometimes held.

1 Samuel 7:6;

2 Chronicles 20:3;

Jeremiah 36:6-10;

Nehemiah 9:1 (Three days after the feast of tabernacles, when the second temple was completed, "the children of Israel assembled with fasting, and with sackcloth and earth upon them," to hear the law read and to confess their sins. (Nehemiah 9:1)

There were also local fasts.

Judges 20:26;

2 Samuel 1:12;

1 Samuel 31:13;

1 Kings 21:9-12;

Ezra 8:21-23:

Jonah 3:5-9.

There are many instances of private occasional fasting (1 Samuel 1:7: 20:34; 2Sam 3:35; 12:16; 1 Kings 21:27; Ezra 10:6; Nehemiah 1:4; Daniel 10:2,3). The instances given of individuals fasting under the influence of grief, vexation or anxiety are numerous.

Moses fasted forty days (Exodus 24:18; 34:28), and so also did Elijah (1 Kings 19:8).

Our Lord fasted forty days in the wilderness (Matthew 4:2).

In the lapse of time the practice of fasting was lamentably abused (Isaiah 58:4; Jeremiah 14:12; Zechariah 7:5). Our Lord rebuked the Pharisees for their hypocritical pretences in fasting (Matthew 6:16). He himself appointed no fast. The early Christians, however, observed the ordinary fasts according to the law of their fathers (Acts 13:3; 14:23; 2Cor 6:5).

In the New Testament the only reference to the Jewish fasts are the mention of "the fast" in (Acts 27:9) (generally understood to denote the day of atonement) an the allusions to the weekly fasts. (Matthew 9:14; Mark 2:18; Luke 5:33; 18:12; Acts 10:30) These fasts originated some time after the captivity.

John Calvin wrote the following on fasting...

Throughout its course, the life of the godly indeed ought to be tempered with frugality and sobriety, so that as far as pos­sible it bears some resemblance to a fast. But, in addition, there is another sort of fasting, temporary in character, when we withdraw something from the normal regimen of living, either for one day or for a definite time, and pledge ourselves to a tighter more severe restraint in diet than ordinarily. (Institutes of Christian Religion)

Matthew Henry (1662-1714) wrote that...

If the solemnities of our fasting, though frequent, long and severe, do not serve to put an edge upon devout affections, to quicken prayer, to increase Godly sorrow, and to alter the temper of our minds, and the course of our lives, for the better, they do not at all answer the intention, and God will not accept them as performed to Him.

William Law (1668-1761) said that...

If religion requires us sometimes to fast and deny our natu­ral appetites, it is to lessen that struggle and war that is in our nature; it is to render our bodies fitter instruments of purity, and more obedient to the good motions of divine grace; it is to dry up the springs of our passions that war against the soul, to cool the flame of our blood, and render the mind more capable of divine meditations. So that although these abstinences give some pain to the body, yet they so lessen the power of bodily appetites and passions, and so increase our taste of spiritual joys, that even these severities of religion, when practiced with discretion, add much to the comfortable enjoyment of our lives. (A Serious Call to A Devout and Holy Life)

The great American Theologian Jonathan Edwards wrote...

One thing more I would mention concerning fasting and prayer, wherein I think there has been a neglect in ministers; and that is that although they recommend and much insist on the duty of secret prayer, in their preaching; so little is said about secret fasting. It is a duty recommended by our Savior to his followers, just in like manner as secret prayer is; as may be seen by comparing the 5th and 6th vs of the 6th chap. of Matt. with vs 16-18. Though I don’t suppose that secret fasting is to be practiced in a stated manner and steady course as secret prayer, yet it seems to me ’tis a duty that all pro­fessing Christians should practice, and frequently practice. There are many occasions of both a spiritual and temporal nature that do properly require it; and there are many par­ticular mercies that we desire for ourselves or friends that it would be proper, in this manner, to seek of God. (Some Thoughts Concerning the Revival)

Phillip Brooks (1835-1893)...

This, then, is the philosophy of fasting. It expresses repentance, and it uncovers the life to God. “Come down, my pride; stand back my passions; for I am wicked, and I wait for God to bless me.”

Andrew Murray (1828-1916)...

Jesus' point is that when a hypocrite fasts, and not only does he not conceal it but he makes it plain to others that he is fasting. But if hypocrisy means "putting on a mask", it would seem at first glance that anointing your face, etc, is hiding from others what you are doing. Isn't hypocrisy trying to look different on the outside from what you really are on the inside? Jesus says that hypocrites demonstrate to others that they are fasting, because as in all of the Sermon on the Mount, He is gazing into our hears! Ouch!

Piper explains that...

the heart that motivates fasting is supposed to be a heart for God. Fasting, in Jesus’ way of seeing things, is a hunger for God, or it is worse than nothing. But the heart that motivates their fasting is a hunger for human admiration. So they are being open and trans-parent about what they are doing, yes, but that very openness is deceptive about what’s in their heart. If they wanted to be really open, they would have to wear a sign about their necks that said, “The bottom-line reward in my fasting is the praise of men.” Then they would not be hypocrites. They would be openly, transparently, unhypocritically vain. But as it is, they hide their vanity and cloak it with fasting. This is their hypocrisy. So there are two dangers that these fasting folks have fallen into. One is that they are seeking the wrong reward in fasting, namely, the esteem of other people. They love the praise of men. And the other is that they hide this with a pretense of love for God. Fasting means love for God—hunger for God. So with their actions they are saying that they have a heart for God. But on the inside they are desperate to be admired and approved by other people.  (Ibid)

Fasting is often connected with vigilant, passionate prayer (cf. Neh. 1:4; Ps. 35:13; Dan. 9:3; Matt. 17:21; Luke 2:37), and includes either a loss of desire for food or the purposeful setting aside of eating to concentrate on spiritual issues

C H Spurgeon's comments...

Use diligence to conceal what it would be foolish to parade. Leave off no outward act of personal cleanliness or adornment; “anoint thine head, and wash thy face. ” If your fasting is unto God, keep it for him. Act in seasons of extraordinary devotion as you do at other times, that those with whom you come in contact may not know what special devotion you are practicing. You may fast, and that lasting may, be discovered; but let it be no intent of, yours that you should “appear unto men to fast. ” Fast from vainglory, ambition, pride, and self-glorification. Fast in secret before the Seer of secrets. Secret fasting shall have an open reward from the Lord; but that which is done out of mere ostentation shall never be reckoned in the books of the Lord. Thus our King has taught us both how to give alms, how to pray, and how to fast; and he will now proceed to legislate for the concerns of daily life. (Commentary)

J C Ryle (1816-1900)...

Noticed by men - Let's all be honest. Whether we have walked with Christ 1 year or 30 years, is this not a challenge in ever area of Christian endeavor, be it preaching, teaching, ushering, etc?  O, how easy it is to do religious things if other people are watching! Preaching, praying, serving, etc all take on a certain pleasantness of the ego if we know that others will find out about our spiritual accomplishments and think well of us.

The natural human tendency in all of us is that deadly addiction for the esteem of others. We all of us a latent desire to be noticed by men! Why? The explanation is simple -- believers still live mortal bodies of frail flesh which house our fallen nature, the "Sin virus" inherited from Adam (note Romans 5:12). But now because we have said "Yes" to Jesus, we have His power in us to say "No" to the old Sin nature that once dominated and contaminated everything we said and did. Now believers can live each new day as more than conquerors in Christ. And yet the battle between the flesh and the spirit is very real, intense and incessant. And thus Paul exhorts us (in the context of believers having difficulty loving one another as they loved themselves - see prior verses)...

But I say, walk (present imperative) by the Spirit, and you will not carry out the desire of the flesh. For the flesh sets its desire against the Spirit, and the Spirit against the flesh; for these are in opposition to one another, so that you may not do the things that you please. But if you are led by the Spirit, you are not under the Law. (Galatians 5:16-17)

The "secret of spiritual success" whether in fasting or any other supernatural endeavor of course is a lifestyle of surrender to our Resident Guide and Teacher, the Spirit of Christ, Who leads us into all righteousness. Because of the believer's identification or union with Christ in His death, burial and resurrection. (See discussion of "Crucified with Christ - Galatians 2:20), we now have His potential within us to enable us to "walk in newness of life" (resurrection power) (See note Romans 6:4), energized by the indwelling Holy Spirit (see notes Ephesians 3:16; Ephesians 5:18). And when we allow Him to fill us and control us, we can fast for the glory of God, caring less for the notice (and praise) of men. Hallelujah, what a great salvation!

In secret - Fast with the clear intention of being seen by your Father, not by men.

Piper reminds us that...

As Jesus teaches it, fasting is an intensely Godward act. Do it toward God, who sees when others don’t. Jesus is testing the reality of God in our lives. Do we really have a hunger for God himself, or a hunger for human admiration?...

What Jesus is doing with these words in Matthew 6 is testing our hearts to see if God himself is our treasure. He is press­ing fasting from the external to the radically internal, and making it a sign of our true Godwardness. “To Judaism, a fast was an outward sign of an inward condition. To Jesus, a fast was an inward sign of an inward condition.” He is testing to see if the admiration of other people or even the spiritual effect on others of our piety has become the God-supplanting food that entices our soul. How do we feel when nobody else knows what we are doing? How is it when no one is saying, “How goes the fast?” Are we content in God when no one but God knows that we have done what we ought to have done?

Jesus is calling for a radical orientation on God himself. He is pushing us to have a real, utterly authentic, personal relationship with God. If God is not real to us—personally, vitally real to us—it will be miserable to endure something difficult with God alone as the One Who knows. It will all seem very pointless, because the whole range of horizontal possibilities will be nullified since no one knows what we are going through. All that matters is God, and Who He is, and what He thinks, and what He will do.  (Ibid)

AND YOUR FATHER WHO SEES WHAT IS DONE IN SECRET WILL REWARD YOU  (See notes Matthew 6:4; 6:6; Romans 2:6; 1 Peter 1:7)

Will reward you - Is not the fact that we are pleasing to our Father reward enough? And yet Jesus says He will reward us. It is good and right to want and to seek the reward of God in fasting. Jesus would not have offered this to us if it were wrong to reach for it. Seeking the reward of the Father is not irreverent or unloving or contrary to true virtue.

Spurgeon wrote that...

When you serve God, do not expect a reward. Be prepared instead to be misunderstood, suspected, and abused. An evil world cannot speak well of holy lives. The sweetest fruit is most pecked at by the birds. The tallest mountains are most battered by the storms. The loveliest character is the most assailed. If you succeed in bringing many to Christ, you will be charged with self-seeking, or popularity hunting, or some such crime. You will be misrepresented, belied, caricatured, and counted as a fool by the ungodly world.

If you serve God, the probabilities are that the crown you win in this world will contain more spikes than sapphires, more briers than emeralds. When it is put on your head, pray for grace to wear it, and count it all joy to be like your Lord. Say in your heart, “I feel no dishonor in this dishonor. The world may attribute shameful things to me, but I am not ashamed. People may degrade me, but I am not degraded. They may look on me with contempt, but I am not contemptible.”

C. S. Lewis wrote that

There are rewards that do not sully motives. A man’s love for a woman is not mercenary because he wants to marry her, nor his love for poetry mercenary because he wants to read it, nor his love for exercise less interested because he wants to run and leap and walk. Love, by definition, seeks to enjoy its object.

Piper adds that...

Doing right “just because it is right” is not the Christian ideal. Doing right to enlarge our delight in God is....

So for the sake of your own soul, and in response to Jesus, and for the advancement of God’s supremacy in all things for the joy of all peoples, comb your hair, and wash your face, and let the Father who sees in secret observe how hungry you are for Him with fasting. The Father Who sees in secret is brimming with rewards for your joy and for his glory.  (Ibid)

Luke describes a woman who was hungering for God and His glory...

And there was a prophetess, Anna the daughter of Phanuel, of the tribe of Asher. She was advanced in years, having lived with a husband seven years after her marriage,  and then as a widow to the age of eighty-four. And she never left the temple, serving night and day with fastings and prayers. And at that very moment (as Simeon was talking with Mary and Joseph) she came up and began giving thanks to God, and continued to speak of Him to all those who were looking for the redemption of Jerusalem. (Luke 2:36-38)

What was Anna's reward? Because of Anna's hunger for God (fastings and prayers), He granted to her the gracious insight of recognizing His Son, her Messiah.

John Piper explains Anna's reward this way...

I think Luke tells us about Simeon and Anna to illustrate the way holy and devout people feel about the promise of Christ’s coming, and how God responds to their longings. They see more than others see. They may not understand fully all the details about how the Messiah is coming—Simeon and Anna surely didn’t—but God mercifully gives them, before they die, a glimpse of what they so passionately wanted to see...Shall we long for him less than Anna longed for him? Does the fact that we have watched him live and love for three years and even now have his Spirit—does this make us feel Anna’s longing less or more? Oh, what an indictment of our blindness or our dullness if the answer is: less.  (Ibid)

Matthew Henry has an interesting comment related to Anna's fastings and prayers writing that...

The Pharisees fasted often, and made long prayers, but they served themselves, and their own pride and covetousness, in their fastings and prayers; but this good woman not only did that which was good, but did it from a good principle, and with a good end; she served God, and aimed at his honour, in fasting and praying. Note ...Those that are diligent and faithful in improving the light and means they have shall have further discoveries made them. Anna is now at length abundantly recompensed for her attendance so many years in the temple.

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F B Meyer (Our Daily Homily) has the following devotional on this passage...

Thy Father which is in secret,… which seeth in secret.

How fondly Jesus repeats these words (Matthew 6:4, 6, 18). Though compelled to live so much in the public gaze of men, his heart was always sighing for the secret place of fellowship with his Father, who waited for Him there.

Of course, the main object of those paragraphs was to withdraw his disciples from the excessive outwardness of the age in which He spoke, and which necessarily detracted from the singleness, directness, and simplicity of the religious life. It is impossible to perform our religious duties before men, without insensibly considering what impression we are producing, and how far their estimation of us is being enhanced. And in so far as we seek these things, the stream is contaminated with mud and silt, and becomes turbid. We have just as much religious life as we show to God in secret — just that, no less, no more. Whatever is not wrought between thee and God, with no record but his eye, is chaff which the wind driveth away.

Here is a test for our alms, our prayers, and our fasting from sin and self-indulgence. If we do any of these to maintain or increase the consideration that men have of us, they count for nothing in the eve of God. But whatever is done for Him alone will secure his inevitable notice and reward. Dwell on that very definite assurance: “Shall recompense thee.” There is no doubt about it. For every petition breathed into his ear; for every sigh and tear; for every abstinence from sin and self there will be a certain recompense, after the Divine measure. Such seeds shall have a prolific harvest. Seek then the secret place, where prying eyes cannot follow, and curious ears cannot overhear.