"And the second time the cock A crew." The Lord turned a mingled look of sadness and rebuke on his disciple. Instantly Peter recalled the prophecy respecting his denial; and the crowing of the cock was like a trumpet-call.... He rushed away to seek some solitary place to vent his overpowering grief. John alone of all his fellow apostles was a witness of Peter's defection, and of this sorrowful scene.... What must he have thought when he saw one who had been so prominent, with whom he had been so intimately associated in the most solemn and tender scenes, so weak and so wicked? He utters not a word, but looks on in silent amazement. It is from him we learn that it was through his intervention Peter gained admission to the palace of the high-priest. But his account of Peter's sin and humiliation is more brief than that of any of the evangelists; while that of Mark, who is commonly supposed to have written under the supervision of Peter himself, is more graphic and full in its details than any other.
—From the Life and Writings of St. John,