(32) There is another . . .--i.e., the Father. The reference to the Baptist is excluded by the words which follow. The difficulty which has been seen in this indirect reference to the Father is removed if we connect the words closely with those preceding them. The point is in the fact that another, different in personality from Himself, bore witness of Him. (Comp. John 8:50; Matthew 10:28, et al.)

I know . . .--This has seemed to have a natural meaning if it is the authority given to John's witness, but to be less fitting if applied to the Father's. In two of the oldest MSS., and some of the earliest versions, we read "ye know," and this has been adopted by some modern editors; but the origin of this reading is obvious, and there is no sufficient reason for departing from the common text. Its meaning is quite in harmony with the relation of the Son to the Father, which has been dwelt upon. The Father beareth witness, is bearing witness (comp. John 5:37), in the unity of work which Son and Father alike work (John 5:17; John 5:19-20; John 5:30), and the Son knows that His power to do this work can come from no other source. His own nature responds to the Father's voice; He knows it to be true. (Comp. John 3:33.)

Verses 32, 37, 38. -

(a) The witness of the Father. Verse 32. - It is another that witnesseth concerning me; and I know that the witness which he witnesseth concerning me is true. It is a mistake, with Ewald, De Wette, and many others, to suppose that this refers to the testimony of John the Baptist. By Augustine, Hengstenberg, Luthardt, Godet, Meyer, etc., it has been perceived that the "other" (ἄλλος) refers to the Father. Jesus expressly declines to receive John's testimony as his justification or sufficient vindication, and he contrasts it with the higher confirmation which in three distinct ways is already and continuously vouchsafed to him. The present tense, μαρτυρεῖ, is in striking contrast to the testimony of John already silenced by imprisonment or death. The methods of this testimony are subsequently analyzed and described. The Father's witness includes -

5:30-38 Our Lord returns to his declaration of the entire agreement between the Father and the Son, and declared himself the Son of God. He had higher testimony than that of John; his works bore witness to all he had said. But the Divine word had no abiding-place in their hearts, as they refused to believe in Him whom the Father had sent, according to his ancient promises. The voice of God, accompanied by the power of the Holy Ghost, thus made effectual to the conversion of sinners, still proclaims that this is the beloved Son, in whom the Father is well pleased. But when the hearts of men are full of pride, ambition, and the love of the world, there is no room for the word of God to abide in them.There is another that beareth witness of me,.... Meaning not his Father, who is another, and a distinct person, from him, as the Spirit is another comforter; and both distinct testifiers from him, as well as of him. This is indeed the sense of some interpreters; but the Father is particularly mentioned in John 5:37; and the thread of the discourse, and the climax, or gradation, here used, show, that it is to be understood of "another man", as Nonnus paraphrases it; of John the Baptist, who is spoken of by name in the next verse, as a witness; and then a greater than he, the works of Christ, and then the Father:

and I know that the witness, which he witnesseth of me, is true; for John was now alive, though in prison, and continued to bear a testimony to Christ; and therefore he speaks of him as now bearing witness of him, and abiding by that which he had bore; and Christ knew not only that what he testified of him was true in itself, but that his testimony was a valid and authentic testimony, with the generality of the Jews; who held John to be a prophet, and looked upon him as a man of great probity and integrity, and whose word was to be taken: nor indeed could the sanhedrim, before whom Christ now was, object to his character, nor to him as a witness; nor ought they, since they themselves had so judged of him, as appears by their message to him, which Christ next fails not to take notice of.