John the Apostle
John 1:15ESV·traditional attribution

(John bore witness about him, and cried out, “This was he of whom I said, ‘He who comes after me ranks before me, because he was before me.’”)

John Calvin Reformed @genevareformer

15. John testifieth. He now relates what was the preaching of John. By using the verb testifieth (μαρτυρεῖ) in the present tense, “En usant du verbe du temps present, a scavoir, Rend tesmoignage, et on pas, Rendoit;” — “by using the verb in the present tense, giveth testimony, and not gave testimony.” he denotes a continued act, and certainly this doctrine must be continually in...

Matthew Henry Presbyterian @wholebiblehenry

In these verses, I. The evangelist begins again to give us John Baptist's testimony concerning Christ, Joh 1:15. He had said (Joh 1:8) that he came for a witness; now here he tells us that he did accordingly bear witness. Here, Observe, 1. How he expressed his testimony: He cried, according to the prediction that he should be the voice of one crying.

Commenting on John 1:15-18

John Gill Reformed Baptist @doctorgill

John bare witness of him,.... Which was his office and business, for which purpose he was sent, Joh 1:6. and cried; this agrees with his work and office, according to the prophecy of him in Isa 40:3 and with the time of his ministry, the year of jubilee; and with the nature of his ministry, which was clear, open, and public; and performed with vigour...