The interpretation timeline
Matthew 6:5 Douay-Rheims

And when ye pray, you shall not be as the hypocrites, that love to stand and pray in the synagogues and corners of the streets, that they may be seen by men: Amen I say to you, they have received their reward.

A.D. 258 – 1871 12 witnesses 26 excerpts

Patristic

before A.D. 750
258
A.D.
c. A.D. 210–258
“(Tr. vii. 2.) The Lord has bid us in His instructions to pray secretly in remote and withdrawn places, as best suited to faith; that we may be assured that God who is present every where hears and sees all, and in the fulness of His Majesty penetrates even hidden places.”
“(Tr. vii. 20.) What insensibility is it to be snatched wandering off by light and profane imaginings, when you are presenting your entreaty to the Lord, as if there were aught else you ought rather to consider than that your converse is with God! How can you claim of God to attend to you, when you do not attend to yourself? This is altogether to make no provision against the enemy; this is when praying to God, to offend God’s Majesty by the neglectfulness of your prayer.”
Source
407
A.D.
John Chrysostom Patristic
A.D. 347–407
“He calls them hypocrites, because feigning that they are praying to God, they are looking round to men; and, He adds, they love to pray in the synagogues.”
“It is a good thing to be drawn away from the thought of empty glory, but especially in prayer. For our thoughts are apt to stray of themselves; if then we address ourselves to prayer with this disease upon us, how shall we understand those things that are said by us?”
“He says, have received, because God was ready to give them that reward which comes from Himself, but they prefer rather that which comes from men. He then goes on to teach how we should pray.”
“He said not ‘shall freely give thee,’ but, shall reward thee; thus He constitutes Himself your debtor.”
420
A.D.
Jerome Patristic
c. A.D. 347–420
“This if taken in its plain sense teaches the hearer to shun all desire of vain honour in praying.”
430
A.D.
Augustine of Hippo Patristic
A.D. 354–430
“(Serm. in Mont. ii. 3.) He does not now bid us pray, but instructs us how we should pray; as above He did not command us to do alms, but shewed the manner of doing them.”
“(ubi sup.) Not that the mere being seen of men is an impiety, but the doing this, in order to be seen of men.”
“(ubi sup.) The privity of other men is to be so far shunned by us, as it leads us to do any thing with this mind that we look for the fruit of their applause.”
“(ubi sup.) Or, by our chambers are to be understood our hearts, of which it is spoken in the fourth Psalm; (Ps 4:4.) What things ye utter in your hearts, and wherewith ye are pricked in your chambers. The door is the bodily senses; without are all worldly things, which, enter into our thoughts through the senses, and that crowd of vain imaginings which beset us in prayer.”
Source
“(ubi sup.) The door then must be shut, that is, we must resist the bodily sense, that we may address our Father in such spiritual prayer as is made in the inmost spirit, where we pray to Him truly in secret.”
435
A.D.
John Cassian Patristic
c. A.D. 360–435
“(Collat. ix. 35.) Also we should observe close silence in our prayers, that our enemies, who are ever most watchful to ensnare us at that time, may not know the purport of our petition.”

Medieval

c. 750 – 1100
908
A.D.
c. A.D. 841–908
“Let it be enough for you that He alone know your petitions, who knows the secrets of all hearts; for He Who sees all things, the same shall listen to you.”

Scholastic

c. 1100 – 1500
1256
A.D.
Thomas Aquinas Catholic
1225–1274
“Peter of Scala, On Matthew, chapter 6, lecture 2: "And when you pray, you shall not be as the hypocrites." Here he removes, in the second place, the desire for human favor from prayer, and this contains three parts. First he excludes the desire for human favor; second he teaches the manner of praying, at "But thou, when thou shalt pray"; third he subjoins the due form of prayer, at "Thus therefore shall you pray," etc. The first part contains three things. First he removes from prayer the ostentation of hypocrites; second, the manner and end of that ostentation, at "who love to stand and pray in the synagogues and corners of the streets"; third he subjoins their condemnation, at "Amen I say to you, they have received their reward." He says therefore "and when you pray," that is, out of the affection of the mind. But here there is a question of the letter: why did he not say, in the singular, "when thou prayest," as he did above, and "when thou doest," etc.? Response: he speaks in the plural, "when you pray," because prayer belongs to all, since nothing temporal is required for it, only the intention of the heart; but giving alms does not belong to all. Or it may be said that prayer is made in two ways: in common, as in choir, and in solitude, etc. "You shall not be as the hypocrites," shining outwardly, foul within, below, chapter 23:27. "Who love." But it is asked why he does not say, "who pray." Chrysostom's response: because in truth they do not pray, but love to be seen as though they were praying. Along the same line it is asked why he did not say the same thing about almsgiving. Response: because although they give alms with an evil intention, they nevertheless give the thing itself. "In the synagogues," where the learned gather to pray, so that they may be seen. "Standing." He says this because it is the custom of the Jews to pray standing, since they received the law standing; Exodus 19:17, "they stood at the foot of the mountain," etc. "And in the corners of the streets," supply: they love to pray. Chrysostom: they seek to hide themselves so that they may be praised in a twofold way: first, because they pray; second, because they pray secretly. "That they may be seen by men." Behold the empty intention. Chrysostom: they do not intend to be heard, but to be seen; likewise the same: O madness of vanity! They do not wish to be what they desire to appear: they pray falsely, since they do not pray; and they are falsely praised, since they are not praiseworthy. They sell an empty semblance of religion, and they buy an empty word of praise. When the word is finished, the good that was placed in the word is also finished. Whence he fittingly subjoins, "Amen I say to you," as if to say: know for certain that "they have received their reward"; the Gloss: human praise; but from me they will receive eternal punishment. "But thou, when thou shalt pray," etc. This is the second part, where he gives the manner of praying. And first he shows the due manner; second he excludes from that manner the rite of the pagans, that is, much speaking, at "And when you are praying, speak not much." The first part is divided into two: first he gives the manner of praying; second he subjoins the promise, at "and thy Father, who seeth in secret, will repay thee." Now the manner of praying consists in three things. First, in the secrecy of meditation; second, in the exclusion of depraved affection, at "and having shut the door"; third, in rectitude of intention, at "pray to thy Father in secret." He says therefore, "but thou, when thou shalt pray, enter into thy chamber," that is, into the secrecy and inner recess of the mind, as Augustine says, and Rabanus, by the act of secret meditation. Chrysostom: God is not to be moved by a clamorous voice, but is to be appeased by a right conscience, for he is a hearer not of the voice but of the heart. Or, "enter into thy chamber" according to the letter. And he pointedly says "chamber," because then the soul ought to rest from external things when it prays; and then is the more fitting time, and the place more secret. Chrysostom: through the day a thousand causes surround you and do not permit you to be secret for prayer. But when you come to your bed, say to your soul: soul, how have we spent the day? What good or evil have we done? Ask God first, and then permit your soul to fall asleep. Thus did Judith, Judith 8:6; thus Peter, Acts 10:9; and Tobias, Tobit 3:10. "And having shut the door," that is, with every depraved and worldly affection excluded, or with the outer senses closed, as the Gloss says. Isaiah 26:20: "Go, my people, into thy chambers, and shut thy doors upon thee." "Pray to thy Father," the Gloss: he who is prayed to in spirit and in truth, John 4:23. Pray, not concerning worldly things. Isidore: far from God is the soul that has been occupied with the thoughts of the age. Jerome: it is one thing to relate to one who does not know, another to ask one who knows: the former is a disclosure, the latter a service. "In secret," that is, in the innermost part of the heart. Chrysostom: let the one praying do nothing new for men to look at, nor cry out with the voice, nor spread out the hands, nor shamelessly lift the eyes to heaven, so as to become conspicuous. "And thy Father, who seeth in secret, will repay thee." Behold, he subjoins the promise, saying, "and thy Father, who seeth in secret," that is, who beholds the heart; Hebrews 4:13: "all things are naked and open to his eyes." "Will repay thee." He does not say "will give," because he has already constituted himself a debtor, that is, he will for certain repay you the reward. Chrysostom: consider the philanthropy of God, that is, the love which he has for men; and consider with wonder the mercy of God, since even for those goods which are asked of him he promises to give a reward. "And when you are praying, speak not much." Here he excludes much speaking from prayer, where first he sets down the prohibition of much speaking; second the reason for the prohibition, at "Be you not therefore like to them." He says therefore, "and when you are praying, speak not much," that is, do not put your trust in words. On the contrary: 1 Thessalonians, last chapter, 17: "Pray without ceasing." Moreover the Lord persevered long in prayer, below, chapter 26:36ff., and Luke 6:12. The response, according to Augustine: he condemns much speaking arising from unbelief, but not the prayers which the saints make in purity of heart. Whence Anselm: it is not a sin to pray with devotion of heart through many words. "As the heathens do," for the gentiles multiplied words in their prayers, first, so that they might indicate their intention to the demons whom they worshiped, since otherwise the demons could not have known it; whence Augustine: for the gentiles a multiplicity of words was necessary on account of the demons. Second, so that they might call back to themselves the demons who were absent; and to this cause Elijah alludes, 1 Kings 18:27, saying to the priests of Baal, when they had prayed for a long time: "Cry with a louder voice: for he is a god, and perhaps he is talking, or is in an inn, or on a journey, or perhaps he is asleep, and must be awaked." Third, so that by the persuasion of words they might incline them to mercy; whence he adds: "for they think that in their much speaking they may be heard," that is, they suppose that by a multitude of persuasive words their prayers are made effective. And because they do so, "therefore be you not," my faithful ones, "like to them," namely in much speaking, so that you should believe God to be inclined by persuasive words. Isidore: men are not heard for their much speaking, as though they were striving by more words to bend God. Likewise, lest you think your God ignorant of what you ask: "for your Father knoweth what is need­ful for you." Behold the reason for the prohibition; as if to say: it is not fitting for you to pray with many words, but with deeds and with a simple affection of heart, says Rabanus. "For your Father knoweth what is need," that is, what is necessary for you, "before you ask him." Why then is it fitting to pray? Response: not that you may teach him, but that you may bend yourself, that you may be made familiar with him, that you may be humbled, that you may be reminded of your sins. And he pointedly says, "your Father." Chrysostom: by saying "Father," he signified in one word both the forgiveness of sins, and the destruction of punishments, and justification, and sanctification, and liberation, and the adoption of sons, and the inheritance of God, and brotherhood joined with the Only-Begotten, and the most abundant gifts of the Holy Spirit. Here Jerome and Rabanus ask: if God knows before we ask, to what purpose do we ask one who knows? Response: manifold is the reason why we speak to one who knows, and why we pray. The first, that we may profess and know that we have from him that which we ask; whence Rabanus: it is not necessary to relate, but to beseech. The second, that an example may be furnished; whence Rabanus: God wishes to be asked, so that his goodness may be conveyed to the peoples. The third, that our mind may be roused; whence Jerome: at the time of prayer we rouse ourselves. The fourth, that devotion may be roused in those standing by. Jerome: we speak, not that we may make a disclosure of our own will, but that we may rouse the service of pious devotion. The fifth, that desire may be kindled. The sixth, that the heart may be purified. Concerning these two the interlinear Gloss: by words the heart is kindled, and by prayers it is made serene. The seventh, that the mind, occupied about holy words, may be withdrawn from superfluous thoughts.”

Post-Reformation

c. 1650 – 1900
1771
A.D.
John Gill Reformed
1697–1771
“And when thou prayest, thou shalt not be as the hypocrites,.... As the Scribes and Pharisees; whose posture in prayer, the places they chose to pray in, and the view they had therein, are particularly taken notice of: for they love to pray standing in the synagogues, and in the corners of the streets, that they may be seen of men. It was their usual custom to pray "standing"; nay, it is established by their canons. "There are eight things, (says Maimonides (u),) that a man that prays ought to take heed to do; and the first he mentions is "standing"; for, says he, no man may pray , "but standing"; if he is sitting in a ship, or in a cart, if he can stand, he must stand; if not, he may sit in his place and pray.'' Several hints of this custom there are in the Misna (w). "On their fast days they used to bring out the ark into the streets-- , "and they stood in prayer", or praying; and caused an old man to go down before the ark, who was used to recite prayers, and he said them.'' Again (x), "whoever , "stood praying", and remembered that any uncleanness attended him, he might not break off, but he might shorten.'' Yea, standing itself is interpreted of praying; for it is said (y), "and Abraham rose up early in the morning to the place, where he stood, , "and there is no prayer but standing";'' though sometimes they prayed sitting, as David did, Sa2 7:18 so it is said of R. Jose, and R. Eleazar, that , "they sat and prayed", and afterwards rose up and went on their way (z). So it was likewise customary to go to the synagogues, and there pray; and indeed they were places built and appointed for this purpose. "Wherever there were ten Israelites, a house ought to be provided, in which they may go to prayer at every time of prayer; and this place is called a synagogue (a).'' Hence some have thought, that not such places are here designed, but any assembly, or concourse of people gathered together upon any occasion; but such an interpretation will find no place, when the following things are observed. "For ever let a man go, morning and evening, to the synagogue; for no prayer is heard at any time, but in the synagogue; and everyone that hath a synagogue in his city, and does not pray in it with the congregation, is called a bad neighbour (b).'' Again (c), "he that prays in the house of the Lord, is as if he offered up a pure offering.'' Now, partly on account of the publicness of the place, and partly because they thought their prayers were only heard there, therefore they chose to pray in the synagogues; and also in the corners of the streets, where two streets met, and they might be the more easily seen. This was also a common thing to pray in the streets: "says R. Jochanan, I saw R. Jannai stand and pray in the streets of Tzippore (d).'' And a little after, it is said of another, that he stood and prayed "in the streets"; though such places were not reckoned holy, as the synagogues were. "The street of a city, (says Maimonides (e),) although the people pray in it at fasts and stations, because that there is a great collection of people, and the synagogues cannot hold them, has no holiness in it, because it is accidental, and not appointed for prayer.'' Wherefore streets were only used in case of necessity, or by such of the Pharisees, who chose to be seen of men. A reason is given for this practice in another place (f), where it is asked, "why do they go out to the streets, i.e. on their fast days? to show that we are reckoned as if we were carried captive before thee: says Joshua ben Levi, because they prayed in "secret", and were not answered; therefore they went without, "that they might be made public".'' Now let it be observed, that neither the posture, nor places of prayer, are condemned by our Lord, but their view in all to be seen of men; and a considerable emphasis lies upon the word "love"; they loved "standing" in prayer, rather than any other posture, because they could be better seen; and they loved to be in the synagogues and streets, rather than in their closets; they liked public better than private prayer, because it gained them applause among men. Verily I say unto you, they have their reward; they gain their point; they have what they seek for; and this is all they will have. (u) Hilch. Tephilla. c. 5. sect. 1, 2. (w) Misn. Taanith, c. 2. sect. 1, 2. (x) Misn. Beracot, c. 3. sect. 5. (y) Zohar in Lev. fol. 47. 1. T. Bab. Beracot, fol. 26. 2. (z) Zohar in Exod. fol. 4. 4. (a) Maimon. Hilch. Tephilla, c. 11. 1. (b) lb. c. 8. sect. 1. T. Bab. Beracot, fol. 8. 1. & Piske Tosephot Beracot, c. 1. art. 7. (c) T. Hieros. Beracot, fol. 8. 4. (d) Ib. fol. 8. 3. & 9. 1. (e) Hilch. Tephilla, c. 11. sect. 21. Vid. Maimon. & Bartenora in Misn. Megilla, c. 3. sect. 1. (f) T. Hieros. Taaniot, fol. 65. 1.”
Source
1849
A.D.
1774–1849
“Hypocrisy is forbidden in all these three good works of justice, but not the doing of them openly for the glory of God, the edification of our neighbour, and our own salvation. Let your light so shine before men, i.e. let your work be so done in public, that the intention remain in secret. (St. Gregory)”
1871
A.D.
1871
“And when thou prayest, thou shalt--or, preferably, "when ye pray ye shall." not be as the hypocrites are: for they love to pray standing in the synagogues and in the corners of the streets--(See on Mat 6:2). that they may be seen of men. Verily I say unto you, They have, &c.--The standing posture in prayer was the ancient practice, alike in the Jewish and in the early Christian Church. But of course this conspicuous posture opened the way for the ostentatious.”
Source

Undated

date unknown
date
unknown
“(non occ.) Solomon says, Before prayer, prepare thy soul. (Ecclus. 18:23.) This he does who comes to prayer doing alms; for good works stir up the faith of the heart, and give the soul confidence in prayer to God. Alms then are a preparation for prayer, and therefore the Lord after speaking of alms proceeds accordingly to instruct us concerning prayer.”
Source
“Prayer is as it were a spiritual tribute which the soul offers of its own bowels. Wherefore the more glorious it is, the more watchfully ought we to guard that it is not made vile by being done to be seen of men.”
“But I suppose that it is not the place that the Lord here refers to, but the motive of him that prays; for it is praiseworthy to pray in the congregation of the faithful, as it is said, In your Churches bless ye God. (Ps. 68:26.) Whoever then so prays as to be seen of men does not look to God but to man, and so far as his purpose is concerned he prays in the synagogue. But he, whose mind in prayer is wholly fixed on God, though he pray in the synagogue, yet seems to pray with himself in secret. In the corners of the streets, namely, that they may seem to be praying retiredly; and thus earn a twofold praise, both that they pray, and that they pray in retirement.”
Source
date
unknown
Glossa Ordinaria Medieval
“(ord.) Or, the corners of the streets, are the places where one way crosses another, and makes four cross-ways.”
date
unknown
“He forbids us to pray in an assembly with the intent of being seen of that assembly, as He adds, that they may be seen of men. He that prays therefore should do nothing singular that might attract notice; as crying out, striking his breast, or reaching forth his hands.”
“Verily I say unto you, they have received their reward, for every man where he sows there he reaps, therefore they who pray because of men, not because of God, receive praise of men, not of God.”
“That none should be there present save he only who is praying, for a witness impedes rather than forwards prayer.”
“We may also understand by the door of the chamber, the mouth of the body; so that we should not pray to God with loudness of tone, but with silent heart, for three reasons. First, because God is not to be gained by vehement crying, but by a right conscience, seeing He is a hearer of the heart; secondly, because none but thyself and God should be privy to your secret prayers; thirdly, because if you pray aloud, you hinder any other from praying near you.”
Source
Modern · 1953 →

The in-app commentary runs from the Fathers to the early-modern record, then stops — that's where the public-domain sources end, not where the reading does. For the modern reading, follow the sources directly.