Catena Aurea

BEDE. (ubi sup.) Thus then John proclaims the Lord not yet as God, or the Son of God, but only as a man mightier than himself. For his ignorant hearers were not yet capable of receiving the hidden things of so great a Sacrament, that the eternal Son of God, having taken upon Him the nature of man, had been lately born into the world of a virgin; but gradually by the acknowledgment of His glorified lowliness, they were to be introduced to the belief of His Divine Eternity. To these words, however, he subjoins, as if covertly declaring that he was the true God, I baptize you with water, but he shall baptize you with the Holy Ghost. For who can doubt, that none other but God can give the grace of the Holy Ghost.

JEROME. For what is the difference between water and the Holy Ghost, who was borne over the face of the waters? Water is the ministry of man; but the Spirit is ministered by God.

BEDE. (ubi sup.) Now we are baptized by the Lord in the Holy Ghost, not only when in the day of our baptism, we are washed in the fount of life, to the remission of our sins, but also daily by the grace of the same Spirit we are inflamed, to do those things which please God.