John Chrysostom — as excerpted in the Catena Aurea on John 18:25-27

“(Hom. lxxxiii) Or, He means that the once fervid disciple was now too torpid, to move even when our Lord was carried away: shewing thereby how weak man’s nature is, when God forsakes him. Asked again, he again denies: They said therefore unto him, Art not thou also one of His disciples? He denied it, and said, I am not.”