A.T. Robertson Commentary John 5:32

"It is another that beareth witness of me; and I know that the witness which he witnesseth of me is true." — John 5:32 (ASV)

Another (αλλος). The Father, not the Baptist who is mentioned in verse 33. This continual witness of the Father (ο μαρτυρων, who is bearing witness, and μαρτυρε, present active indicative) is mentioned again in verses 36-38 as in 8:17.