Luke 9:18-21 King James Version (KJV)
18 And it came to pass, as he was alone praying, his disciples were with him: and he asked them, saying, Whom say the people that I am?
19 They answering said, John the Baptist; but some say, Elias; and others say, that one of the old prophets is risen again.
20 He said unto them, But whom say ye that I am? Peter answering said, The Christ of God.
21 And he straitly charged them, and commanded them to tell no man that thing;