Cross reference
John 5:31
31 "If I testify about myself, my witness is not valid.
Proverbs 27:2
2 Let another man praise you, And not your own mouth; A stranger, and not your own lips.
John 8:13-14
13 The Pharisees therefore said to him, "You testify about yourself. Your testimony is not valid."
14 Jesus answered them, "Even if I testify about myself, my testimony is true, for I know where I came from, and where I am going; but you don't know where I came from, or where I am going.
John 8:54
54 Jesus answered, "If I glorify myself, my glory is nothing. It is my Father who glorifies me, of whom you say that he is our God.
Revelation 3:14
14 "To the angel of the assembly in Laodicea write: "The Amen, the Faithful and True Witness, the Head of God's creation, says these things: