Matthew 16:18

Verse 18. And I say also unto thee, That thou art Peter. The word Peter, in Greek, means a rock. It was given to Simon by Christ when he called him to be a disciple, Joh 1:42. Cephas is a Syriac word, meaning the same as Peter--a rock, or stone. The meaning of this phrase may be thus expressed: "Thou, in saying that I am the Son of God, hast called me by a name expressive of my true character. I, also, have given to thee a name expressive of your character. I have called you Peter, a rock, denoting firmness, solidity; and your confession has shown that the name is appropriate. I see that you are worthy of the name, and will be a distinguished support of my religion. And upon this rock, etc.