Interesting insight into the words themselves, and that appears to be exactly how Augustine is reading them as well:
“”For petra (rock) is not derived from Peter, but Peter from petra; just as Christ is not called so from the Christian, but the Christian from Christ.”
IOW, the “pebble” derives from the “rock,” which is Christ.
*You are pebble and on this pebble I am going to build my church*?
I suppose that for the Catholic church, that just might be about right.
For the rest of us redeemed, we are being built on the chief cornerstone - The Rock.