Augustine of Hippo — as excerpted in the Catena Aurea on John 13:12-20

“(Tr. lix. 1) They then who were chosen ate the Lord; he ate the bread of the Lord, to injure the Lord; they ate life, he damnation; for he that eateth unworthily, eateth damnation to himself. (1 Cor. 11:27) Now I tell you before it come, that when it is come, ye may believe that I am He, i. e. of whom that Scripture foretold.”