Second Council of Constantinople
Catena Aurea · Matthäusevangelium 16
When Jesus came into the coasts of Cæsarea Philippi, he asked his disciples, saying, Whom do men say that I the Son of man am? And they said, Some say that thou art John the Baptist; some, Elias; and others, Jeremias, or one of the prophets. He saith unto them, But whom say ye that I am? And Simon Peter answered and said, Thou art the Christ, the Son of the living God. And Jesus answered and said unto him, Blessed art thou, Simon Barjona: for flesh and blood hath not revealed it unto thee, but my Father which is in heaven. And I say also unto thee, That thou art Peter, and upon this rock I will build my Church: and the gates of hell shall not prevail against it. And I will give unto thee the keys of the kingdom of heaven: and whatsoever thou shalt bind on earth shall be bound in heaven: and whatsoever thou shalt loose on earth shall be loosed in heaven.
(Concil. Con. ii. Collat. 8.) How is it that some do presume to say that these things are said only of the living? Know they not that the sentence of anathema is nothing else but separation? They are to be avoided who are held of grievous faults, whether they are among the living, or not. For it is always behoveful to fly from the wicked. Moreover there are divers letters read of Augustine of religious memory, who was of great renown among the African bishops, which affirmed that heretics ought to be anathematized even after death. (vid. Aug. Ep. 185. 4.) Such an ecclesiastical tradition other African Bishops also have preserved. And the Holy Roman Church also has anathematized some Bishops after death, although no accusation had been brought against their faith in their lifetimeu.