This oil painting is based on John 1:29.

John Testifies About Jesus

29 The next day John saw Jesus coming toward him and said, “Look, the Lamb of God, who takes away the sin of the world! 30 This is the one I meant when I said, ‘A man who comes after me has surpassed me because he was before me.’ 31 I myself did not know him, but the reason I came baptizing with water was that he might be revealed to Israel.”