The Father bears witness of Jesus
John 5:37
37 And the Father himself, which hath sent me, hath borne witness of me. Ye have neither heard his voice at any time, nor seen his shape.
John 8:18
18 I am one that bear witness of myself, and the Father that sent me beareth witness of me.
1 John 5:9
9 If we receive the witness of men, the witness of God is greater: for this is the witness of God which he hath testified of his Son.