Ask, and it will be given to you; seek, and you will find; knock, and it will be opened to you: Aiteite, (2PPAM) kai dothesetai (3SFPI) humin; zeteite, (2PPAM) kai euresete; (2PFAI) krouete, (2PPAM) kai anoigesetai (3SFPI) humin. (Mt 7:11; 21:22; 1 Kings 3:5; Psalms 10:17; 50:15; 86:5; 145:18,19; Isaiah 55:6,7; Jeremiah 29:12,13; 33:3; Mark 11:24; Luke 11:9,10,13; 18:1; John 4:10; John 14:13,14; 15:7,16; 16:23,24; James 1:5,6; 5:15; 1 John 3:22; 5:14,15; Revelation 3:17,18) (6:33; Psalms 10:4; 27:8; 69:32; 70:4; 105:3,4; 119:12; Proverbs 8:17; Song of Solomon 3:2; Amos 5:4; Romans 2:7; 3:11; Hebrews 11:6) (Luke 13:25)
 

See Related Resources on Prayer...

Gems on Prayer by C H Spurgeon
Prayer Resources
Global Prayer Digest Operation World
Praying for Your Missionaries Guide to specific daily prayers:
Prayer for Deeper Understanding - Wayne Barber:
Prayer for Fullness - Wayne Barber
Notes on the "Disciple's Prayer" Matthew 6:9ff
Notes on praying for hope, joy, peace Romans 15:13

Notes on praying for enlightenment, etc Ephesians 1:18, 19, 20
Notes on praying for inner strength Ephesians 3:14, 15, 16, 17, 18

Notes on Paul's "complete" prayer Colossians 1:9, 10, 11, 12ff
Notes on praying when anxious Philippians 4:6, Philippians 4:7

Notes on prayer for loving discernment Philippians 1:9, 10, 11, 12

Notes on praying without ceasing 1Thessalonians 5:17

Spurgeon wrote that...

Faith asks, hope seeks, and love knocks.

***

Here is a three-fold encouragement to us to pray. When we cannot use one style of prayer, let us use another, for each shall be successful at the right time. O child of God, let nothing keep thee from prayer! It has been well said that a Christian may be hedged in, but he cannot be roofed in; there is always a passage way upwards to the throne of the great Father; and asking, knocking, seeking, he shall be sure to be successful with his suit.

***

To men you may not always speak of heavenly things, but to God you may.

“Ask, seek, knock”; let your prayer be adapted to the case; let it increase in intensity, let it advance in the largeness of its object. To receive a gift is simple, to find a treasure is more enriching, to enter into a palace is best of all. Each form of prayer is prescribed, accepted, and rewarded in a manner suitable to its character. The promise is universal to all who obey the precept. The commands are in opposition to the methods of carking care which have been denounced in the former chapter; and they are encouragements to the precepts of giving and non-recessional set forth previously, since he that can have of God for the asking may well give to men who ask, and even yield to those who unjustly demand. With such boundless stores at command, we should not be either niggardly or litigious. Lord, help me to have done with fretting, and to abound in asking, seeking, knocking; so shall I soon overflow with thanksgiving.

Kent Hughes gives an important caveat regarding this well known verse warning that...

 The instruction in this text should not be lifted from its context (Ed note" see importance of context in accurate interpretation and valid application) in the Sermon and abused. All of us have heard this done. "The Bible says, 'Ask, and it shall be given to you; seek, and you shall find; knock, and it shall be opened to you.' Therefore, all we have to do is ask for it with faith and persistence, and we will get it. 'You do not have because you do not ask' (James 4:2). So go for it! Name it and claim it!" This view sees God as a celestial slot machine. Pull the handle enough times in prayer, be persistent, and you will get what you want! Such thinking is entirely wrong! A text without a context is a pretext. Isolating this text from its setting in the Sermon on the Mount is deadly. The broad context of the Sermon sets down the surpassing righteousness, humility, sincerity, purity, and love expected of those who are members of the kingdom of God. These virtues are beyond human attainment apart from God's grace. The broad context underscores our need. In the immediately preceding context (vv. 1-6) Jesus has shown us the danger of condemning other people as if we were judges. He also has told us to get the plank out of our own eye before we attempt to remove a speck from someone else's. His warning is, "For in the same way you judge others, you will be judged, and with the measure you use, it will be measured to you" (v. 2). This standard is terrifying. Who is adequate for such things? How can we live up to such a high standard? We need to be cleansed. We need help and grace, but from where? Jesus answers, "Ask and it will be given to you; seek and you will find; knock and the door will be opened to you" (v. 7). This famous text is not carte blanche for our material desires. Rather, it tells us how to pray for the character of the kingdom in our lives. (Hughes, R. K. Sermon on the Mount: The Message of the Kingdom. Crossway Books) (Bolding added)

Ray Pritchard feels that...

There are at least three things that hinder us from going deeper in prayer. The first is the sneaking suspicion that prayer doesn’t matter. It’s easy to fall into a kind of fatalism that says “God’s gonna do what God’s gonna do.” So we stop praying because we think nothing will change. Then there is the fear that we won’t pray in the “right” way, that we won’t use the correct words or we won’t use the right formula and that God therefore won’t even bother to hear what we say. Finally most of us struggle with the little voice inside that tells us we’ve got more important things to do. Prayer is good but we need to get on with the “real business” of the day. So we don’t pray as we ought or as we would like.  (Matthew 7:7-11 Three Levels of Prayer)

Ask (154) (aiteo) means to ask for with urgency, even to the point of demanding. Aiteo more frequently suggests attitude of a suppliant (one who supplicates [supplicate is from Latin supplex = bowed] means to makes a humble, earnest plea or entreaty), the petitioning of one who is lesser in position than he to whom the petition is made. To ask means to to call on for an answer, which indicates that we believe there is someone (our Father) listening. It also implies that we expect Him to answer or otherwise why ask? The self-righteous person does not ask but tells God how good he is (see parable Luke 18:10-13).

Spurgeon in his book Power in Prayer notes that...

It may be a revealing exercise for some of you to find out how often in Scripture you are told to pray. You will be surprised to find how many times such words as these are given: “Call upon Me in the day of trouble, and I will deliver thee” (Psalm 50:15). “Ye people, pour out your heart before Him” (Psalm 62:8). “Seek ye the LORD while He may be found; call ye upon Him while He is near” (Isaiah 55:6). “Ask, and it shall be given you; seek, and ye shall find; knock, and it shall be opened unto you” (see note Matthew 7:7). “Watch ye and pray, lest ye enter into temptation” (Mark 14:38). “Pray without ceasing” (see note 1Thessalonians 5:12). “Come boldly unto the throne of grace” (see note Hebrews 4:16). “Draw nigh to God and He will draw nigh to you” (James 4:8). “Continue in prayer” (see notes Colossians 4:2). I need not multiply what I could not possibly exhaust. I pick two or three out of this great bag of pearls.

Asking is what beggars do and that is exactly what those who are "poor in spirit" (see notes Matthew 5:3) are! In poor countries beggars unashamedly stand by the road with their hands held out, asking alms for the poor. Sometimes they can be quite bold about it and even irritating to passers by. In those moments it helps to remember that you would be bold too if you were in their position. And in a spiritual sense we are in their position for we have brought nothing into the world and can take nothing out. We are totally dependent on God the Father of lights from Whom every good thing bestowed and every perfect gift comes (cf James 1:17). But unlike beggars on the streets, citizens of the Kingdom of Heaven have access through Jesus to our Father Who art in heaven!

Jesus has already explained that in His omniscience, our...

Father knows what you need, before you ask Him. (notes Matthew 6:8)

By asking we nurture our relationship with our Father. He delights to hear and to answer His children as Jesus explains in the following verses.

We need to be more like apostle James of whom Eusebius wrote that his...

knees grew hard like a camel’s because of his constant worship of God, kneeling and asking forgiveness for the people.

Edward Payson said

Prayer is the first thing, the second thing, the third thing necessary to minister. Pray, therefore, my dear brother, pray, pray, pray.”

Seek (2212) (zeteo) means to attempt to learn something by careful investigation or searching,  to desire to have or experience something or to try to obtain something from someone. Seeking is asking plus acting, implying earnest petitioning coupled with an active endeavoring to fulfill needs. When you seek something, you rearrange your priorities so that you can search for what you desire until you find it. Do you prioritize prayer?

Seeking implies a desire for something of great value. A good illustration of this is Jesus' analogy that...

the kingdom of heaven is like a merchant seeking fine pearls, and upon finding one pearl of great value, he went and sold all that he had, and bought it. (Mt 13:45-46)

Or think about Jesus’ story of the woman searching for a lost coin...

"Or what woman, if she has ten silver coins and loses one coin, does not light a lamp and sweep the house and search carefully until she finds it?' (Luke 15:8)

or the shepherd with 100 sheep who, having lost one, left the 99 and went searching for the one sheep that had gone astray. It is like a man seeking a pearl of great price, who having found it, gives all that he has in order to purchase it.

Puritan Thomas Manton wrote that "If we don’t receive by asking, then let us seek; if we don’t receive by seeking, then let us knock."

Spurgeon notes that...

This is the simplest form of prayer. Follow up your prayer by the effort. “Knock, and it shall be opened unto you.” Add force to your petitions and to your prayers. If the door blocks the way, knock until it is opened...

Prayer knocks till the door opens. Open it will, for so runs the promise of our faithful God, "To him that knocketh it shall be opened." "If the angel opened the door of the prison to let Peter out, it was prayer that opened the door of heaven to let the angel out."

Knock (2925) (krouo) means to rap at a door for entrance and thus implies an even greater and more repetitive intensity than either asking or seeking. The English word "knock" comes from German word meaning to press! “Knock” means to stand at a door and repeatedly rap it with your knuckles. You knock and wait, then you knock again, then you say, “I know you’re in there,” then you knock again and say, “I can hear your voice. Come on, open the door.” Then you knock again. If you’re on the other side, you know how annoying it can be to listen as someone knocks and knocks and keeps on knocking. But that’s precisely the picture behind Jesus' command to keep on knocking! The idea might imply praying in the face of difficulty and even resistance. If you knock like this, your desire for entrance must be very great indeed.

Note the ascending degree of intensity from asking then to seeking and finally to overtly knocking! Each of these verbs is in the present imperative, which is a command to do each of these activities continually. Jesus is calling for persistence in prayer. Prayer is as necessary to us as oxygen to our life. Prayer is the lifeline for citizens of the Kingdom of heaven who are still on earth and as such it expresses our continued dependence on Him as we beseech Him for the grace and power to live the supernatural life of surpassing righteousness that Jesus has described in this Sermon. In order to live out the righteousness we must ask and keep asking, seek and keep seeking and knock and keep knocking.

Spurgeon wrote that...

There was a nailhead for the knocker to drop on, and people used to smite it so heavily that some remarked that such blows on the head were killing. Hence arose the mirthful proverb, "as dead as a doornail." It betokens a hearty kind of knocking, which I would have you imitate in prayer. Knock at heaven's gate as ear­nestly as people knocked at doors in the olden time

Hughes observes that...

Ask implies asking for a conscious need. The word also suggests humility in asking, for it is commonly used of one asking a superior. The next step, seek, involves asking but adds action. The idea is not merely to express one's need, but to get up and look around for help. It involves effort. Knock includes asking plus acting plus persevering - like someone who keeps pounding on a closed door!

The stacking of these words is extremely forceful, but the fact that they are present imperatives gives them even more punch... Jesus is driving his point home, and the point is this: We are to passionately persist in prayer. We naturally persevere in our prayers when someone close to us is sick. If one of our children becomes ill, we pray without ceasing. Likewise, if we are in financial trouble or if we are hoping for a promotion or if we have a frightening or dangerous task ahead of us, we generally find it easy to pray. But do we persist in our prayers for spiritual growth for ourselves and others? Do we "ask . . . seek . . . knock" for a pure mind? Do we keep on knocking for a forgiving spirit or for the removal of an angry or critical spirit? (Hughes, R. K. Sermon on the Mount: The Message of the Kingdom. Crossway Books) (Bolding added)

Keep in mind that this charge to a lifestyle of prayer is situated at the end of the description of a kingdom citizen that began in Matthew 5:20 (note) and immediately precedes Jesus' call to enter the narrow gate, the gate of divine righteousness (ultimately the righteousness of Christ Himself, cp 1 Cor 1:30) that surpasses that of the man-made righteousness of the scribes and Pharisees. Supernatural righteousness is not reckoned on the basis of works but only on the basis of faith in the finished work of the Messiah on the Cross. But to continue to live this righteousness in our daily walk necessitates faith and continued dependence upon God's grace and His Spirit. In this context Jesus inserts this powerful command to persistent prayer that is to be part of the righteous lifestyle of Kingdom citizens and is fact critical for us to be enabled to continually walk worthy of the gospel to which we were called. Jesus is not saying prayer is an after thought but in fact is to be our first thought and our continual thought.

William MacDonald agrees with this analysis writing that...

If we think that we can live out the teachings of the Sermon on the Mount by our own strength, we have failed to realize the supernatural character of the life to which the Savior calls us. The wisdom or power for such a life must be given to us from above. So here we have an invitation to ask and keep on asking; to seek and keep on seeking; to knock and keep on knocking. Wisdom and power for the Christian life will be given to all who earnestly and persistently pray for it.  Taken out of context (Ed note: see critical role of context in accurate interpretation), verses 7 and 8 might seem like a blank check for believers, i.e., we can get anything we ask for. But this is simply not true. The verses must be understood in their immediate context and in light of the whole Bible’s teaching on prayer. Therefore, what seems like unqualified promises here are actually restricted by other passages. For example, from Psalm 66:18 we learn that the person praying must have no unconfessed sin in his life. The Christian must pray in faith (Ja. 1:6-8) and in conformity with the will of God (1Jn. 5:14). Prayer must be offered persistently (Luke 18:1-8) and sincerely (Heb 10:22a) (MacDonald, W., & Farstad, A. Believer's Bible Commentary: Old and New Testaments. Nashville: Thomas Nelson) (Bolding added)

Phil Newton explains it this way...

How often have we heard the command of verse 7 to be a carte blanche confirmation to ask God for anything we desire? It seems that this is most often the application of the well-known asking, seeking, knocking command of prayer. But I would insist that this is an improper use of this prayer. In this Sermon we do not have a string of random thoughts and sayings of Jesus collated by Matthew into a single literary format – which would legitimize carte blanche use of this command. Instead we have a consistent picture of the character and demands upon kingdom citizens. The command to pray in verse 7 has everything to do with fulfilling kingdom demands....

(Jesus) is calling for a lifestyle of persistent prayer. That stands in sharp contrast to the flash-in-the-pan style of Christianity so popular in our day that calls for nothing but a profession (and maybe baptism) and lacks perseverance. Kingdom citizens persist in desiring that the character, ambitions, attitudes, and behavior that Jesus called for be shown consistently in our lives. Yet we realize how impossible this is given our weaknesses, our propensity for sin, and our lack of power to obey (we have not forgotten the first Beatitude – “blessed are the poor in spirit, for theirs is the kingdom of heaven”). So our Lord tells us to call upon the God of the impossible! In other words, what Jesus has commanded in attitude, ambition, behavior, and deed cannot be done apart from persistent, ongoing, regular, faithful prayer. You can attend dozens of seminars on Christian living, participate in discipleship groups, and read all the good books on the subject including the Puritans. But if you are not regular in praying about your own spiritual needs and development, and persistently looking to the Lord for grace to follow Christ, then you will be sorely lacking in the practice of kingdom citizenship.

Persistent prayer does at least three things in our lives.

First, it reminds us of our weakness apart from God’s grace. If we ever get away from this we are destined for a great fall.

“Therefore, let him who thinks he stands take heed that he does not fall” (1 Cor 10:12 – and that stated in the context of temptation).

We are reminded of our inadequacies in the face of Christ’s demands. We think upon the desperate condition of our hearts, and our helplessness to stand against the “schemes of the devil” that are daily aimed our way (see note Ephesians 6:11). As we are honest before the Lord we come face to face with our sinfulness, and desperate need for the gospel to be daily applied to our lives.

Second, it reminds us to look to God as our Father. Perhaps nothing is more lacking in our lives than this very thing. We know the confessions, creeds, and hymns that affirm that God is our Father. But do we look to Him persistently as our Father that loves and cherishes us? Martyn Lloyd-Jones commented,

“If you should ask me to state in one phrase what I regard as the greatest defect in most Christian lives I would say that it is our failure to know God as our Father as we should know Him” [The Sermon on the Mount, II, 202].

And I would add, the most prominent reason for this defect is our neglect and inconsistency in prayer. In effect, by neglecting prayer, we treat God as a casual friend and not as “Our Father who is in heaven” (6:9). Yet the Father promises to “give what is good to those who ask Him!”

Third, it disciplines and humbles us to receive the Father’s gracious provisions so that we might live as kingdom citizens. We are affected by dispositions of heart and the influences around us. So often we think that we have the “stuff” to do whatever God commands if we make our mind up to do it. And so we get a bit cocky and arrogant, while growing in self-centeredness as the natural course of human existence. We are also influenced by what we see and hear in the world to be selfish. But prayer brings us back to reality: we are inadequate in ourselves to live the Christian life apart from God’s grace. So we ask and go on asking, seek and go on seeking, and knock and go on knocking so that we might receive from the Father what we need to live like kingdom citizens. And in persistent prayer the Lord develops in us a dependency and submission to Him. (Matthew 7:7-12 Prayer and Practice) (Bolding added)

The Disciple's Study Bible comments that...

Asking suggests dependence; seeking suggests yearning; knocking suggests persistence. Jesus wanted to encourage faith. These verses should not be applied out of the context of the Sermon on the Mount; they are intended for those asking within the "narrow gate'' of Jesus' followers. Prayer is to accomplish God's purposes. (Disciple's Study Bible)

The Wycliffe Bible Commentary offers another explanation for Jesus' introduction of prayer at this point. This explanation addresses the more immediate context of necessary judging (but by no means excludes need for prayer brought out by interpreting it in the larger context discussed above)...

(these) verses on prayer (cf. Lk 11:9-13) answer the believer’s problems arising from the instructions on judging. The need of discerning between dogs and swine while avoiding the beam in the eye demands wisdom from above. Hence Jesus encourages his followers to ask, seek, and knock, that their deficiencies may be met from the divine supply. The three imperatives are in climactic order, and their durative forms suggest not only perseverance but frequent prayer for any and all needs. (Wycliffe Commentary)

Arthur Pink has a well reasoned explanation of why Jesus mentions prayer at this point and note that his analysis also relies heavily on the context...

What has been suggested above concerning the scope of our present passage will be the more apparent by viewing it in relation to its whole context. From Mt 5:20, onwards, Christ had presented a standard of moral excellence which is utterly unattainable by mere flesh and blood. He had inculcated one requirement after another, which it lies not in the power of fallen human nature to meet. He had forbidden an opprobrious word, a malignant wish, an impure desire, a revengeful thought. He had enjoined the most unsparing mortification of our dearest members (Mt 5:29, 5:30). He had commanded the loving of our enemies, the blessing of those who curse us, the doing good unto those who hate us, and the praying for those who despitefully use and persecute us (Mt 5:44). In view of which the Christian may well exclaim, “Who is sufficient for these things?” Such demands of holiness are beyond my feeble strength: yet the Lord has made them—what then am I to do?

Coming nearer still to our passage we find that in the opening verses of chapter 7 Christ gave two apparently contradictory commands. First, He says, “Judge not, that ye be not judged:” abstain from forming harsh estimates and passing censorious censures on your fellows. Second, “Give not that which is holy unto the dogs:” discriminate sharply between the clean and the unclean, that you may not be guilty of obliterating the line which God has drawn between the righteous and the wicked. But to steer safely between such rocks as these requires not only spiritual strength but spiritual wisdom, such wisdom as the natural man possesses not. What then is the poor believer to do? The Lord here anticipates this difficulty and meets this perplexity. He is well aware that, in our own wisdom and strength, we are incapable of keeping His commands, but He at once reminds us that the things which are ordinarily impossible to men can be made possible to them by God.

(Ed note: But if any of you lacks wisdom, let him ask of God, who gives to all men generously and without reproach, and it will be given to him. But let him ask in faith without any doubting, for the one who doubts is like the surf of the sea driven and tossed by the wind. James 1:5-6)

Divine assistance is imperative if we are to meet the Divine requirements. The Divine assistance is to be sought prayerfully, believingly, diligently and persistently, and if it be thus sought it will not be sought in vain. It was then for the obtaining of supplies of Divine grace and heavenly strength that our Lord now exhorted and encouraged His disciples. “Ask, and it shall be given you; seek, and ye shall find; knock, and it shall be opened unto you” (Mt 7:7).

In the foregoing chapter Christ had touched upon the subject of prayer in a way of warning, but here He refers to it as the appointed channel for obtaining supplies of grace to obey those precepts which are so contrary to flesh and blood. First He had given instructions concerning the duty of prayer, but now He supplies gracious encouragements for the exercise of it. Nevertheless, it is clear from the general tenor of scripture that every other legitimate means must be employed if we are to obtain the strength and help we so much need. (Matthew 7:7-8: Seeking Grace)

Spurgeon in his sermon Knock writes...

I Have no doubt that, taken very strictly, the three exhortations of this verse-which, indeed, are but one-were first of alt intended for God’s believing people. It was to his disciples that the Lord said, “Cast not your pearls before swine;” and perhaps certain of them who were poor in spirit might turn round and say, “Lord, we have few pearls; we are too poor to have the treasures of thy grace so plentifully. Thou hast bidden us not to give that which is holy unto dogs; but holiness is rather a thing we seek after than possess.” “Well,” saith the Lord, “you have only to ask and have; ye have not because ye ask not; you have only to seek and you will be sure to find, for holy things, like rare pearls, are to be discovered if you look for them you have only to knock and spiritual secrets shall open to you, even the innermost truth of God.” In each exhortation our Lord bids us pray. Beloved, let us abound in supplication. depend upon it that failure in prayer will undermine the foundation of our peace and sap the strength of our confidence; but if we abound in pleading with God we shall grow strong in the Lord, and we shall be happy in his love, we shall become a blessing to those around us. Need I commend the mercy-seat to you who wait before it? Surely prayer must have become such a joy to you, such a necessity of your being, such an element of your life, that I hardly need press it upon you as a duty, or invite you to it as a privilege. Yet still I do so, because the Master does it by a triple exhortation. A threefold cord is not easily broken-let not my text be neglected by you. Let me urge you to repeated, varied, ever intensifying prayer: ask! seek! knock! Cease not to ask till you receive; cease nor to seek till you find; cease not to knock till the door is opened unto you.

In these three exhortations there would appear to be a gradation: it is the same thought put into another shape, and made more forcible.

Ask-that is, in the quiet of your spirit, speak with God concerning your need, and humbly beg him to grant your desires: this is a good and acceptable form of prayer.

If, however, asking should not appear to succeed, the Lord would arouse you to a more concentrated and active longing; therefore let your desires call in the aid of knowledge, thought, consideration, meditation, and practical action, and learn to seek for the blessings you desire as men seek for hid treasures. These good things are laid up in store, and they are accessible to fervent minds. See how you can reach them. Add to asking the study of the promises of God, a diligent hearing of his word, a devout meditation upon the way of salvation, and all such means of grace as may bring you the blessing. Advance from king into seeking.

And if after all it should still seem that you have not obtained your desire, then knock and so come to closer and more agonizing work; use not alone the voice, but the whole soul; exercise yourself unto godliness to obtain the boon; use every effort to win that which you seek after; for remember that doing is praying; living to God is a high form of seeking, and the bent of the entire mind is knocking. God often giveth to his people when they keep his commandments that which he denies to them if they walk carelessly.

Remember the words of the Lord Jesus, how he said, “If ye abide in me, and my words abide in you, ye shall ask what ye will, and it shall be done unto you.”

Holiness is essential to power in prayer: the life must knock while the lips ask and the heart seeks.

I will change my line of exposition and say: ask as a beggar petitions for aims. They say that begging is a poor trade, but when you ply it well with God no other trade is so profitable. Men get more by asking than by working without prayer. Though I do not discommend working, yet I most highly commend praying. Nothing under heaven pays like prevailing prayer. He that has power in prayer has all things at his call. Ask as a poor mendicant who is hungry and pleads for bread. Then seek as a merchant who hunts for goodly pearls, looking up and down, anxious to give all that he has that he may win a matchless treasure.

Seek as a servant carefully looking after his master’s interests and laboring to promote them. Seek with all diligence, adding to the earnestness of the beggar the careful watchfulness of the jeweler who is seeking for a gem.

Conclude all by knocking at mercy’s door as a lost traveler caught out on a cold night in a blinding sleet knocks for shelter that he may not perish in the storm. When you have reached the gate of salvation ask to be admitted by the great love of God, then look well to see the way of entering, seeking to enter in; and if still the door seem shut against you, knock right heavily, and continue knocking till you are safely lodged within the home of love.

Once again, ask for what you want, seek for what you have lost, knock for that from which you are excluded.

Perhaps this last arrangement best indicates the shades of meaning, and brings out the distinctions.

Ask for everything you need, whatever it may be: if it be a right and good thing, it is promised to the sincere asker.

Seek for what you have lost; for what Adam lost you by the Fall, for what you have lost yourself by your neglect, by your backsliding, by your want of prayer: seek till you find the grace you need.

Then knock. If you seem shut out from comfort, from knowledge, from hope, from God, from heaven, then knock, for the Lord will open unto you. Here you need the Lord’s own interference: you can ask and receive, you can seek and find; but you cannot knock and open,-the Lord must himself open the door, or you are shut out for ever.

God is ready to open the door. Remember, there is no cherub with fiery sword to guard this gate, but, on the contrary, the Lord Jesus himself openeth, and no man shutteth. (Read the full text Matthew 7:7 Knock! - Pdf)

D A Carson comments on why prayer is mentioned at this point in the Sermon explaining that...

the Sermon on the Mount lays down the righteousness, sincerity, humility, purity, and love expected of Jesus' followers; and now it assures them such gifts are theirs if sought through prayer.

The sermon has begun with acknowledgment of personal bankruptcy (notes Matthew 5:3) and has already provided a model prayer (notes Mt 6:9-10, 6:11-12, 6:13). Now (Mt 7:7) in three imperatives (ask, seek, knock) symmetrically repeated (Mt 7:8) and in the present tense to stress the persistence and sincerity required (cf. Jer 29:13 God to Judah "And you will seek Me and find Me, when you search for Me with all your heart.&qu