The interpretation timeline
John 18:27 Douay-Rheims

Again therefore Peter denied; and immediately the cock crew.

A.D. 407 – 1871 5 witnesses

Patristic

before A.D. 750
407
A.D.
John Chrysostom Patristic
A.D. 347–407
“(Hom. lxxxiii. 3) But neither did the garden bring back to his memory what he had then said, and the great professions of love he had made: Peter then denied again, and immediately the cock crew.”

Scholastic

c. 1100 – 1500
1270
A.D.
Thomas Aquinas Catholic
1225–1274
“The Lord's response having been set forth, here the rebuke of that response is set forth, and first the rebuke by the servant is set forth; second, the Lord's satisfaction, where it says "Jesus answered him," etc. Now the servant rebukes the Lord's response, first indeed by deed, because he gave him a blow as a reproach; hence it says "when he had said these things," namely Jesus, "one of the servants standing by," namely of the high priest, "gave him a blow." This indeed did not happen by chance, but had been prophesied long before and in many ways; Isaiah 50:6: "I have given my body to those who strike, and my cheeks to those who pluck them"; Lamentations 3:30: "He will give his cheek to the one striking him, he will be filled with reproaches"; Micah 5:1: "With a rod they shall strike the cheek of the judge of Israel." Second, he rebukes by word, saying, "Do you answer the high priest thus?" In which it is given to understand that Annas was high priest and had not yet sent him to Caiaphas; hence Luke 3:2 mentions these two high priests: "under the high priests," he says, "Annas and Caiaphas." But they are called two high priests because they claimed the high priesthood for themselves in alternating turns; but in that year Annas was the chief of the priests. Now the servant was moved to strike Jesus from this, namely because he had appealed to the testimony of those who heard him — above, John 7:32: "when the high priests had sent servants to seize him, they themselves, captivated by the words of Jesus, returned saying, 'never has a man spoken thus, as this man.'" Wishing therefore to excuse himself here, that he was not one of them, he struck him. But he conjectured that Christ had answered the high priest badly from this, because by what he said, "Why do you question me? Ask those who have heard," he seemed to have marked the high priest as guilty of an imprudent question, whereas nevertheless it is written, Exodus 22:28: "You shall not curse the ruler of your people." Consequently Jesus reasonably excuses himself when he says, "If I have spoken evil" — answering the high priest — "bear witness of the evil," as if to say: if you have, from those things that were brought forth by me, something from which you could rebuke me, show that I have spoken evil; for "every word stands by the mouth of two or three witnesses," Deuteronomy 19:15. "But if well" — that is, if you cannot show this — "why do you strike me?" That is, why do you rage against me? Or this can be referred back to what he said above, "ask those who heard what I said to them," so that the sense is: if I have spoken evil, in the synagogue and in the temple, what I ought not to have, bear witness of the evil that I spoke before the chief of the priests. But this the servant could not have shown. But if well — namely, if I taught rightly — why do you strike me? As if to say, it is unjust; Jeremiah 18:20: "Shall evil be repaid for good, since they have dug a pit for my soul?" But here there is a question, because at Matthew 5:39 the Lord commands his disciples: "If anyone strikes you on the right cheek, offer him the other also." But of Christ it is said, Acts 1:1: "Jesus began to do and to teach." He ought therefore to have done what he taught. But he did not do this; rather — what seems the contrary — he excused himself. Response. It must be said, according to Augustine, that the sayings and precepts of sacred Scripture can be interpreted and are understood from the deeds of the saints, since the same Holy Spirit who inspired the prophets and the other authors of sacred Scripture also moved the saints to action. For, just as it is said at 2 Peter 1:21, "inspired by the Holy Spirit, the holy men of God spoke"; so at Romans 8:14 it is said: "those who are led by the Spirit of God, these are the sons of God." Thus sacred Scripture is to be understood according to what Christ and the other saints observed. But Christ did not offer this man the other cheek; nor did Paul, Acts 16:22ff. Hence it is not to be understood that Christ had commanded that they offer, according to the letter, the other bodily cheek to him who strikes one; but this ought to be understood as to the preparation of the mind, namely that if it should be necessary, one ought to be so disposed that he not be disturbed in mind against the one striking him, but be prepared to endure the like, and even more. And this the Lord observed, who offered his own body to be slain. Thus therefore the Lord's excusing of himself was useful for our instruction. Here it is shown how he is sent from the high priest to another high priest, and first Jesus' sending is set forth; second, Peter's denial is completed, where it says "Now Simon Peter was standing and warming himself." It says therefore, "and Annas sent him bound to Caiaphas the high priest," to whom he was being led from the beginning; but the reason why he had first turned aside there was expressed above. But note the wickedness of Annas: because although he ought to have released him, as being without fault, he nevertheless sent him bound. Here the second and third denials of Peter are treated, and first the occasion of the denial is set forth; second, Peter's twofold denial, where it says "they said therefore to him," etc.; third, the fulfillment of the sign of Christ's words is set forth, where it says "and immediately the cock crowed," etc. Now the occasion of Peter's second denial was his lingering with the servants of the high priest standing at the fire. For Chrysostom says: when Christ withdrew to Caiaphas, Peter still remained with the servants. For he was so absorbed by sin after his denial that he who before was fervent now no longer seemed to care about Christ; Jeremiah 8:6: "There is no one who does penance for his sin, saying, 'What have I done?'" And therefore it says, "Now Simon Peter was still standing and warming himself"; although Christ had withdrawn from there, forgetful of what is said in Psalm 1: "Blessed is the man who has not gone in the counsel of the wicked." But this exposition cannot stand: because thus it would follow that the second and third denial had been made in Christ's absence; which is against what is said at Luke 22:61, that after Peter's third denial the Lord turned and looked upon Peter. And therefore Augustine, expounding otherwise, says that the Evangelist speaks by recapitulation, according to his custom, in order to show the continuity and order of the matter. For he had said above that the servants and attendants were standing at the coals, because it was cold, and were warming themselves, and Peter was standing with them, and warming himself; and afterward he inserted the account of Christ's examination by the high priest; and subsequently, in order to continue the series, he resumes, as it were, the same words, saying "Now Simon Peter was standing" — namely, before Christ was sent to Caiaphas. Then Peter's twofold denial is set forth, when it says, "They said therefore to him: Are you not also one of his disciples?" And concerning each, two things are set forth, namely the occasion of the denial, that is, the questioning, and the denial itself. But here a twofold literal question arises. For Matthew 26:71, speaking of the second denial, says: "But as he was going out the gate, another maidservant saw him, and said to those who were there: This man also was with Jesus of Nazareth. And again he denied with an oath." And thus there seems here a twofold contrariety. Because John said that Peter denied while standing at the fire, but Matthew, while he was going out of the house. The other contrariety is: because according to Matthew he is questioned by another maidservant, but according to John by others, namely by many, whence it says, "They said therefore to him: Are you not also one of his disciples?" Likewise also, according to Luke, he is questioned by only one, whence at Luke 22:59 it is said: "And an interval having elapsed of about one hour, a certain other man affirmed, saying: Truly this man also was with him." Response. It must be said that when Peter denied the first time, he rose and went out the gate, and as he was going out another maidservant questioned him. Or she said to others that he was one of them, as Matthew relates. And thus he denied the second time. And afterward Peter returned in order to excuse himself of this also, and sat with the others; and while he was sitting there, others who had heard from the maidservant again questioned him, as Matthew says. Or one first, as is said here, and afterward many others. And thus he denied the third time. Hence it is added concerning the third denial: "One of the servants of the high priest, a kinsman of him whose ear Peter had cut off, said." This third one bore witness, because from having seen him, whence he says: "Did I not see you in the garden with him?" Again therefore Peter, an interval of about one hour having elapsed, denied, the third time. Nor does it matter if the other Evangelists say the third questioning was made by several, while John says it was made by one. For it could happen that this one, who was more certain, questioned, and incited the others to question. For many things were said around these words by the bystanders, of which one Evangelist records one thing, and another another, since their principal intention was not directed to this, but to recording the words of Peter, and to showing the truth of what the Lord had said to Peter; hence in Peter's words all agree; Numbers 24:13: "Whatever the Lord shall say, this I will speak." Consequently he treats of the sign of Christ's remembrance: hence it says, "and immediately the cock crowed," moved by divine power, so that the prediction of the physician might be fulfilled, and the presumption of the sick man convicted.”

Post-Reformation

c. 1650 – 1900
1771
A.D.
John Gill Reformed
1697–1771
“Peter then denied again,.... A third time, as the Ethiopic version renders it; and that, according to other evangelists, with cursing and swearing; for now he was more affrighted than before, lest should he be taken up, and it be proved upon him, that he was the person that cut off Malchus's ear, he should be sentenced to a fine, or it may be some capital punishment. The fine for plucking a man's ears, and which some understand of plucking them off, was four hundred "zuzim" (s), or, pence; which, as they answer to Roman pence, amount to twelve pounds ten shillings; a sum of money Peter perhaps could not have raised, without great difficulty: and therefore, that it might be believed he was not a disciple of Christ, so not the man; he swears in a profane manner, and imprecates the judgments of God upon him: and immediately the cock crew; the second time; which was a signal by which he might call to remembrance, what Christ had said to him; that before the cock crowed twice, he should deny him thrice, Mar 14:72. It was now early in the morning, about three o'clock, or somewhat after. (s) Misn. Bava Kama, c. 8, sect. 6. Vid. L'Empereur in ib.”
Source
1832
A.D.
Adam Clarke Methodist
1762–1832
“And - the cock crew - Peter denied our Lord three times: - Peter's First Denial. I. This took place, when he was without, or beneath, in the hall of Caiaphas's house. He was not in the higher part where Christ stood before the high priest; but without that division of the hall, and in the lower part with the servants and officers, at the fire kindled in the midst of the hall, Joh 18:16, Joh 18:18; and the girl who kept the door had entered into the hall, where she charged Peter. Peter's Second Denial. II. This was in a short time after the first, Luk 22:58. Having once denied his Master, he naturally retired from the place where his accuser was to the vestibule of the hall, Mat 26:71, and it was the time of the first cock-crowing, or soon after midnight. After remaining here a short time, perhaps an hour, another girl sees him, and says to them who were standing by in the vestibule, that he was one of them. Peter, to avoid this charge, withdraws into the hall, and warms himself. The girl, and those to whom she had spoken, follow him; the communication between the two places being immediate. Here a man enforces the charge of the girl, according to Luke; and others urge it, according to St. John; and Peter denies Jesus vehemently. Peter's Third Denial. III. He was now in the hall, and also within sight of Jesus, though at such a distance from him that Jesus could not know what passed, but in a supernatural way. And, about an hour after his second denial, those who stood by founded a third charge against him, on his being a Galilean, which St. Luke says, Luk 22:59, one in particular strongly affirmed; and which, according to John, Joh 18:26, was supported by one of Malchus's relations. This occasioned a more vehement denial than before, and immediately the cock crew the second time, which is eminently called αλεκτοροφωνια. The first denial may have been between our twelve and one; and the second between our two and three. At the time of the third denial, Luk 22:61 proves that Jesus was in the same room with Peter. We must farther observe that Matthew, Mat 26:57, lays the scene of Peter's denials in the house of Caiaphas: whereas John, Joh 18:15-23, seems to intimate that these transactions took place in the house of Annas; but this difficulty arises from the injudicious insertion of the particle ουν, therefore, in Joh 18:24, which should be omitted, on the authority of ADES, Mt. BH, many others; besides some versions, and some of the primitive fathers. Griesbach has left it out of the text. See Bishop Newcome's Harm. notes, p. 48. The time of Peter's denials happened during the space of the third Roman watch, or that division of the night, between twelve and three, which is called αλεκτοροφωνια, or cock-crowing, Mar 13:35. Concerning the nature and progress of Peter's denial, see the notes on Mat 26:58, Mat 26:69-75.”
Source
1871
A.D.
1871
“Peter then denied again--But, if the challenge of Malchus' kinsman was made simultaneously with this on account of his Galilean dialect, it was no simple denial; for Mat 26:74 says, "Then began he to curse and to swear, saying, I know not the man." So Mar 14:71. This was THE THIRD DENIAL. and immediately--"while he yet spake" (Luk 22:60). the cock crew--As Mark is the only Evangelist who tells us that our Lord predicted that the cock should crow twice (Mar 14:30), so he only mentions that it did crow twice (Mar 14:72). The other Evangelists, who tell us merely that our Lord predicted that "before the cock should crow he would deny Him thrice" (Mat 26:34; Luk 22:34; Joh 13:38), mention only one actual crowing, which was Mark's last. This is something affecting in this Evangelist--who, according to the earliest tradition (confirmed by internal evidence), derived his materials so largely from Peter as to have been styled his "interpreter," being the only one who gives both the sad prediction and its still sadder fulfilment in full. It seems to show that Peter himself not only retained through all his after-life the most vivid recollection of the circumstances of his fall, but that he was willing that others should know them too. The immediately subsequent acts are given in full only in Luke (Luk 22:61-62): "And the Lord turned and looked upon Peter," from the hall of judgment to the court, in the way already explained. But who can tell what lightning flashes of wounded love and piercing reproach shot from that "look" through the eye of Peter into his heart! "And Peter remembered the word of the Lord, how He had said unto him, Before the cock crow, thou shalt deny Me thrice. And Peter went out and wept bitterly." How different from the sequel of Judas' act! Doubtless the hearts of the two men towards the Saviour were perfectly different from the first; and the treason of Judas was but the consummation of the wretched man's resistance of the blaze of light in the midst of which he had lived for three years, while Peter's denial was but a momentary obscuration of the heavenly light and love to his Master which ruled his life. But the immediate cause of the revulsion, which made Peter "weep bitterly," was, beyond all doubt, this heart-piercing "look" which his Lord gave him. And remembering the Saviour's own words at the table, "Simon, Simon, Satan hath desired to have you that he may sift you as wheat, but I have prayed [rather, 'I prayed'] for thee that thy faith fail not" (see on Luk 22:31-32), may we not say that this prayer fetched down all that there was in that 'look' to pierce and break the heart of. Peter, to keep it from despair, to work in it "repentance unto salvation not to be repented of," and at length, under other healing touches, to "restore his soul?" (See on Mar 16:7).”
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.