Mark 8:27-30

And Jesus went forth, and his disciples, into the villages of Cæsarea Philippi: and on the way he asked his disciples, saying unto them, Who do men say that I am? And they told him, saying, John the Baptist; and others, Elijah; but others, One of the prophets. And he asked them, But who say ye that I am? Peter answereth and saith unto him, Thou art the Christ. And he charged them that they should tell no man of him.