It is another who testifies about me. I know that the testimony which he testifies about me is true.

(iii) So he adduces the witness of his works. He had done that when John sent from prison to ask if he was the Messiah. He had told John's enquiring envoys to go back and tell him what they saw happening ( Matthew 11:4; Luke 7:22). But Jesus cites his works, not to point to himself but to point to the power of God working in him and through him. His supreme witness is God. 