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

“(Tr. lix. 1) As if to say, There is one among you who will not be blessed, nor doeth these things. I know whom I have chosen. Whom, but those who shall be happy by doing His commandments? Judas therefore was not chosen. But if so, why does He say in another place, Have not I chosen you twelve? Because Judas was chosen for that for which he was necessary, but not for that happiness of which He says, Happy are ye, if ye do them.”