Ambrosiaster : This is not recorded in the Gospels, but Paul knew it independently of them. — COMMENTARY ON PAUL'S EPISTLES Cyril of Jerusalem : "He appeared to Cephas; and after that to the twelve." So if you disbelieve one witness, you have twelve witnesses. "Then he was seen by more than five hundred people at once"—if they disbelieve the twelve, then listen to the five hundred. "After that he was seen by James," his own brother and the first overseer of this [Jerusalem] diocese. Since so noteworthy a bishop was privileged to see the risen Christ, along with the other disciples, do not disbelieve. But you may say that his brother was a biased witness. So then he continues: "He was seen by me." But who am I? I am Paul, his enemy! "I was formerly a persecutor" but now preach the good news of the resurrection. — Catechetical Lecture 14:22 John Chrysostom : "Then he appeared to above five hundred brethren at once; of whom the greater part remain until now, but some are fallen asleep." Some say that "above," is above from heaven; that is, "not walking upon earth, but above and overhead He appeared to them:" adding, that it was Paul's purpose to confirm, not the resurrection only, but also the ascension. Others say that the expression, "above five hundred," means, "more than five hundred." "Of whom the greater part remain until now." Thus, "though I relate events of old," saith he, "yet have I living witnesses." "But some are fallen asleep." He said not, "are dead," but, "are fallen asleep," by this expression also again confirming the resurrection. — Homily on 1 Corinthians 38 Shepherd of Hermas : Those square white stones which fitted exactly into each other, are apostles, bishops, teachers, and deacons, who have lived in godly purity, and have acted as bishops and teachers and deacons chastely and reverently to the elect of God. Some of them have fallen asleep, and some still remain alive. And they have always agreed with each other, and been at peace among themselves, and listened to each other. — Shepherd of Hermas, Vision 3