Matthew 26:34

(Verse 34.) Jesus said to him: Truly I say to you, that in this night before the rooster crows, you will deny me three times. And Peter, with fervor of faith, promised, and the Savior, as if God, knew the future. And note that Peter will deny in the night, and deny a third time. But after the rooster crowed, and the darkness diminishing, the approaching light was announced, he turned and wept bitterly, washing away the stains of denial with tears of repentance.

(de Cons. Ev. iii. 4.) Perplexity may be occasioned to some by the great difference, not in words only, but in substance, of the speeches in which Peter is forewarned by Our Lord, and which occasion his presumptuous declaration of dying with or for the Lord. Some would oblige us to understand that he thrice expressed his confidence, and the Lord thrice answered him that he would deny Him thrice before cock-crowing; as after His resurrection He thrice asked him if he loved Him, and as often gave him command to feed His sheep. For what in language or matter has Matthew like the expressions of Peter in either Luke or John? Mark indeed relates it in nearly the same words as Matthew, only marking more precisely in the Lord's words the manner in which it should fall in, Verily I say unto thee, that this day, in the night, before the cock crow twice, thou shalt deny me thrice. (Mark 14:30.) Whence some inattentive persons think that there is a discrepancy between Mark and the rest. For the sum of Peter's denials is three; if the first then had been after the first cock crowing, the other three Evangelists must be wrong when they make the Lord say that Peter should deny Him before the cock crow. But, on the other hand, if he had made all three denials before the cock began to crow, it would be superfluous in Mark to say, Before the cock crow twice. Forasmuch as this threefold denial was begun before the first cockcrow, the three Evangelists have marked, not when it was to be concluded, but how often it was to happen, and when to begin, that is, before cock-crow. Though indeed if we understand it of Peter's heart we may well say, that the whole denial was complete before the first cock-crow, seeing that "before that his mind was seized with that great fear which wrought upon him to the third denial. Much less therefore ought it to disquiet us, how the three-fold denial in three distinct speeches was begun, but not finished before cockcrow. Just as though one should say, Before cock-crow you will write me a letter, in which you will revile me three times; if the letter were begun before any cock-crow, but not finished till after the first, we should not therefore say that the prediction was false.