Augustine of Hippo
Catena Aurea · Matthäusevangelium 3
I indeed baptize you with water unto repentance: but He that cometh after me is mightier than I, Whose shoes I am not worthy to bear: He shall baptize you with the Holy Ghost, and with fire: Whose fan is in His hand, and He will throughly purge His floor, and gather His wheat into the garner; but He will burn up the chaff with unquenchable fire.
(in Joann. Tract. v. 5.) Or, he baptizes, because it behoved Christ to be baptized. But if indeed John was sent only to baptize Christ, why was not He alone baptized by John? Because had the Lord alone been baptized by John, there would not have lacked who should insist that John’s baptism was greater than Christ’s, inasmuch as Christ alone had the merit to be baptized by it.