I saw and testified. He means that what he declares is not doubtful; because God was pleased to make him fully and thoroughly acquainted with those things of which he was to be the witness to the world; and it is worthy of notice, that he testified that Christ was the Son of God, because he who gives the Holy Spirit must be the Christ, for to no other belongs the honor and the office of reconciling men to God.

And I saw, and bare record that this is (r) the Son of God.
(r) This word "the" points out to us some excellent thing, and makes a distinction between Christ and others, whom Moses and the prophets commonly call the sons of the most High.

And I saw,.... The Spirit descending from heaven as a dove, and lighting upon Jesus, and remaining some time on him; this he saw with his bodily eyes:
and bore record; at the same time, before all the people that were with him, when he baptized Jesus:
that this is the Son of God; the natural, essential, and eternal Son of God; who being sent in the fulness of time, had assumed an human nature, in which he became subject to all ordinances, and had the Spirit without measure bestowed on him; and which was an evidence who he was, and of what he came about.

I saw it - That is, the Spirit so descending and abiding on him. And testified - From that time.