In Mark 8:29, Yeshua asked His disciples who they thought He was. Was He merely a rabbi? A prophet? Or someone greater?
Simon Peter replied on behalf of the rest, identifying Yeshua as the Messiah, the Son of God. The Master responded by identifying Simon as “The Rock.” He did not give him the name here. All four Gospels use the name Peter throughout. According to John 1:42, the Master gave Simon the nickname when He first laid eyes upon him: “‘You are Simon the son of [Jonah]; you shall be called Cephas’ (which is translated Peter).”
The word “Cephas” is a Greek transliteration of the Aramaic word for “rock” (kefa). The Gospel of John explains that kefa means the same as the Greek word petros, i.e., “rock.” Shim’on bar Yonah seems to have been known thereafter by both epithets: Kefa (Cephas) and Petros (Peter).
Punning off of His chief disciple’s nickname, the Master said to Simon, “I also say to you that you are Petros, and upon this petra (rock) I will build My assembly.”
Much has been made of the wordplay between the Greek Petros and petra, but how is such wordplay possible if Yeshua spoke Hebrew or Aramaic? The Greek word petra appeared as a common loanword in rabbinic Hebrew. Simon probably answered to both Petros and Kefa. As the first to make an explicit confession of faith in the messianic identity of Yeshua, Simon Peter became the foundation for Messiah’s assembly. The Master’s words appear to allude to an old parable about Abraham:
A parable: Once there was a king who sought to build a palace. He began to dig, going further down, to lay a foundation, but he found only swampy soil. And so it was in many places. He was not able to build until he dug in one place, and there he found a bed of rock (petra). Thus he said, “I am building and placing foundations here,” and he built. So too, the Holy One, blessed be He, sought to create the world. He was sitting and scrutinizing the generation of Enosh and the generation of the flood, and He said, “For what shall I create the world and let those wicked men arise and vex me?” But when the Holy One, blessed be He, saw Abraham arise in the future, he said, “Behold, I have found rock (petra) to build upon and to lay the foundation of the world.” Thus he called Abraham “Rock,” as it says, [in Isaiah 51:1-2], “Look to the rock from which you were hewn,” and he called Israel “rocks.” (Yalkut Shim’oni)
The parable uses the Greek petra in Hebrew as a loanword and identifies Abraham as the petra upon which the LORD founded the world. The parable is so similar to Matthew 16:18 that the two texts must be related.
In what way is the disciple Simon Peter the petra-foundation of the Master’s assembly? The nineteenth-century Messianic Jewish commentator Rabbi Lichtenstein explains that Peter was the first to proclaim Messiah to the Jewish people and the first to proclaim the gospel to the Gentiles. He founded the first community of Yeshua-followers in Jerusalem, and he laid the foundation for the work among the Gentiles at the house of Cornelius.