Giovanni 1:42

And he brought him to Jesus. And when Jesus beheld him, he said, Thou art Simon the son of Jona: thou shalt be called Cephas, which is by interpretation, A stone. Cephas, which is by interpretation, A stone - Πετρος signifies a stone, or fragment of a rock. The reason why this name was given to Simon, who was ever afterwards called Peter, may be seen in the notes on Matteo 16:18, Matteo 16:19, and particularly in Luke, at the end of chap. 9.