Jesus gave one of his apostles, Simon, a new name. He called him, "Peter," an interesting word that previously was not used as a proper name.
The Gospels were originally written in Greek and the word used is petros, meaning "rock." An article on Catholic Answers explains what this word meant in Greek.
Furthermore, according to the Ignatius Catholic Study Bible, "evidence suggests that Jesus' words to Peter were originally spoken in Aramaic. In this language, the word kepha is the equivalent of Peter and denotes a 'sizeable rock' -- one suitable as a building foundation. This Aramaic name is preserved [in its Latinized form] as Cephas 9 times in the New Testament."
This is why the Church continues to teach that Jesus appointed Peter as the foundation stone of the Catholic Church.
Jesus also said these words at Caesarea Philippi, a city that was literally built on a massive rock!
The Catholic Encyclopedia explains, "It was given (20 B.C.) by Augustus to Herod, who built there a magnificent temple in honor of the emperor. Soon after, the tetrarch Philip embellished it and dedicated it to his imperial protector Tiberius, whence its new name Caesarea Philippi or Caesarea Paneas."
This helps give more context to Jesus' actions, who was pointing out how Simon would be the "rock" for his Church, in contrast to the rock that the temple at Caesarea Philippi was built on.