68 But he denied, saying, I know not, neither understand I what thou sayest. And he went out into the porch; and the cock crew.
[AD 430] Augustine of Hippo on Mark 14:66-72
(ubi sup.) We must understand by this, that the Lord suffered these things till morning, in the house of the High Priest, whither He had first been brought.

(ubi sup.) Concerning the temptation of Peter, which happened during the injuries before mentioned, all the Evangelists do not speak in the same order. For Luke first relates the temptation of Peter, then these injuries of the Lord; but John begins to speak of the temptation of Peter, and then puts in some things concerning our Lord's ill-treatment, and adds, that He was sent from there to Caiaphas the High Priest, and then he goes back to unfold the temptation of Peter, which he had begun. Matthew and Mark on the other hand first notice the injuries done to Christ, then the temptation of Peter. Concerning which it is said, And as Peter was beneath in the palace, there cometh one of the maids of the High Priest.

(ubi sup.)y This maid is not the same, but another, as Matthew says. Indeed we must also understand, that in this second denial he was addressed by two persons, that is, by the maid whom Matthew and Mark mention, and by another person, of whom Luke takes notice. It goes on: And he denied it again. Peter had now returned, for John says that he denied Him again standing at the fire; wherefore the maid said what has been mentioned above, not to him, that is, Peter, but to those who, when he went out, had remained, in such a way however that he heard it; wherefore coming back and standing again at the fire, he contradicted them, and denied their words. For it is evident, if we compare the accounts of all the Evangelists on this matter, that Peter did not the second time deny him before the porch, but within the palace at the fire, whilst Matthew and Mark who mention his having gone out are silent, for the sake of brevity, as to his return.

[AD 735] Bede on Mark 14:66-72
(upi. sup.) But what can be meant by his being first recognised by a woman, when men were more able to know him, if it be not that that sex might be seen to sin in the death of our Lord, and that sex be redeemed by His Passion? It goes on: But he denied, saying, I know not, neither understand I what thou sayest.

(ubi sup.) The other Evangelists do not mention this crowing of the cock; they do not however deny the fact, as also some pass over many other things in silence, which others relate. There follows: And a maid saw him again, and began to say to them that stood by, This is one of them

(ubi sup.) By this denial of Peter we learn, that not only he denies Christ, who says that He is not the Christ, but he also, who although he is a Christian, denies himself to be such. For the Lord did not say to Peter, Thou shalt deny thyself to be my disciple, but, Thou shalt deny me; he therefore denied Christ, when he said that he was not His disciple. There follows: And a little after, they that stood by said again to Peter, Surely thou art one of them, for thou art a Galilæan, and thy speech agreeth thereto. Not that the Galilæans spoke a different tongue from the inhabitants of Jerusalem, for they were both Hebrews, but that each province and region has its own peculiarities, and cannot avoid a vernacular pronunciation.

(ubi sup.) How hurtful is it1 to speak with the wicked. He denies before infidels that he knows the man, whom amongst the disciples, he had confessed to be God. But the Scripture is wont to point out a Sacrament2 of the causes of things, by the state of the time; thus Peter, who denied at midnight, repented at cock crow; wherefore it is added: And the second time the cock crew. And Peter called to mind the word which Jesus said unto him, Before the cock crow twice, thou shalt deny me thrice. And he began to weep.

[AD 1107] Theophylact of Ohrid on Mark 14:66-72
The Lord allowed this to happen to him by His providence, that is, lest he should be too much elated, and at the same time, that he might prove himself merciful to sinners, as knowing from himself the result of human weakness. There follows: And he went out into the porch; and the cock crew.

Therefore Peter was seized with fear, and for-getting the word of the Lord, which said, Whosoever shall confess me before men, him will I confess before my Father, (Matt. 30, 32) he denied our Lord; wherefore there follows: But he began to curse and to swear, saying, I know not this man of whom ye speak.

For tears brought Peter by penitence to Christ. Confounded then be the Novatians, who say that he who sins after receiving baptism, is not received to the remission of his sin. For behold Peter, who had also received the Body and Blood of the Lord, is received by penitence; for the failings of saints are written, that if we fall by want of caution, we also may be able to run back through their example, and hope to be relieved by penitence.

[AD 1274] Pseudo-Jerome on Mark 14:66-72
Peter when he had not the Spirit yielded and lost courage at the voice of a girl, though with the Spirit he was not afraid before princes and kings.

But in a mystical sense, the first maid means the wavering, the second, the assent, the third man is the act. This is the threefold denial which the remebrance of the word of the Lord washes away through tears. The cock then crows for us when some preacher up our hearts by repentance to compunction. We then begin to weep, when we are set on fire within by the spark of knowledge, and we go forth, when we cast out what we were within.

[AD 735] Bede on Mark 14:68
And he went out before the courtyard, and the cock crowed. Of this crowing of the cock, the other evangelists are silent, though they do not deny that it happened, just as many others pass over in silence many things which others recount.