John Chrysostom — as excerpted in the Catena Aurea on John 13:36-38

“(Hom. lxxiii. 1) It is manifest that our Lord permitted Peter’s fall. He might have recalled him to begin with, but as he persisted in his vehemence, though He did not drive him to a denial, He let him go without assistance, that He might learn his own weakness, and not fall into such sin again, when the superintendence of the world had come to him, but that remembering what had happened to himd, he might know himself.”