I believe Matthew 16:18. Jesus is telling Peter that his confession of faith is “the rock” not the man himself.
Jesus may very well have been talking about Peters faith
being the rock, but he also said he was giving him the key to the kingdom.
We can say that Jesus was talking to all of the apostles
but proving it is something else,
The Catholic Church teaches more than enough UNsscriptual
doctrine that I think we can give them the benefit of the doubt on this.