Jesus: You are Peter (petros in original Greek - small rock - common name Peter) and upon this rock (petra - large rock - Peter’s statement of faith) I will build my church. The article briefly mentions the argument, and correctly dismisses it. It's wrong for three reasons:
- "Petra" has feminine gender, and so is unsuitable as a man's given name. Matthew has to change it to the masculine "Petros" to be Peter's name.
- Jesus and Peter probably weren't speaking Greek to each other anyway; the alleged "pebble vs. big rock" play on words doesn't exist in Aramaic or Hebrew.
- "petros" as a noun meaning "pebble" is known only from a few examples in classical Greek poetry, not in Koine.
Several Protestant exegetes -- Ridderbos is one of the more notable examples -- agree that your reading is untenable. Finally, let it be noted that you will never hear the Greek Orthodox apologetic against the Papacy cite this argument. Presumably, you would agree with me that the Greek Orthodox know Greek!