Not all of the early church fathers interpreted Mt 16 as the "rock" referring to Peter. That is, sometimes they believed that the faith of Peter was the foundation of the church and could not be defeated by hell. Others viewed the "Rock" of Mt 16 as Jesus Christ Himself. Here are two quotations on Christ as the "Rock." I also would like to suggest to you that if a church father believed that the "rock" was Peter it did not follow that they meant it referred to the "Bishop of Rome" alone but was for a plurality and equality of
eldership leadership. If Rome was set apart in early history it was because of their geological location not because the "Bishop of Rome" was the leader of the "universal" church of our Lord and Savior Jesus Christ. However, here are some quotations from Jerome and John of Damascus. I have the references upon request.
Jerome (347-420) wrote,
"She, that with a firm root is founded upon the rock, Christ, the Catholic Church, is the one dove; she stands the perfect one, and near to His right hand, and has nothing sinister in her."
"The rock is Christ, Who gave to His apostles, that they also should be called rocks, "Thou art Peter, and upon this rock I will build My Church."
"Was there no other province in the whole world to receive the gospel of pleasure, and into which the serpent might insinuate itself, except that which was founded by the teaching of Peter upon the rock Christ."
John of Damascus (645-749) wrote,
"The rock was Christ, the incarnate Word of God, the Lord, for Paul clearly teaches us: 'The rock was Christ' (I Cor. 10:4)."