“Be it known to you, my lord, that Simon [Peter], who, for the sake of the true faith, and the most sure foundation of his doctrine, was set apart to be the foundation of the Church, and for this end was by Jesus himself, with his truthful mouth, named Peter” (Letter of Clement to James 2 [A.D. 221]).
-The Letter of Clement to James
“Look at [Peter], the great foundation of the Church, that most solid of rocks, upon whom Christ built the Church [Matt. 16:18]. And what does our Lord say to him? ‘Oh you of little faith,’ he says, ‘why do you doubt?’ [Matt. 14:31]” (Homilies on Exodus 5:4 [A.D. 248]).
-Origen
“[Christ] made answer: ‘You are Peter, and upon this rock will I build my Church. . . .’ Could he not, then, strengthen the faith of the man to whom, acting on his own authority, he gave the kingdom, whom he called the rock, thereby declaring him to be the foundation of the Church [Matt. 16:18]?” (The Faith 4:5 [A.D. 379]).
-Ambrose of Milan
“Simon Cephas answered and said, ‘You are the Messiah, the Son of the living God.’ Jesus answered and said unto him, ‘Blessed are you, Simon, son of Jonah: flesh and blood has not revealed it unto thee, but my Father which is in heaven. And I say unto thee also, that you are Cephas, and on this rock I will build my Church; and the gates of hades shall not prevail against it” (The Diatesseron 23 [A.D. 170]).
-Tatian the Syrian
“Was anything withheld from the knowledge of Peter, who is called ‘the rock on which the Church would be built’ [Matt. 16:18] with the power of ‘loosing and binding in heaven and on earth’ [Matt. 16:19]?” (Demurrer Against the Heretics 22 [A.D. 200]).
-Tertullian