4 Give heed to this, exercise your discrimination, and know it, beloved. The baptism which John received is called the baptism of John: alone he received such a gift. No one of the just before him and no one after him so received a baptism that it should be called his baptism. He received it indeed, for of himself he could do nothing: for if any one speaks of his own, he speaks of his own a lie. And whence did he receive it except from the Lord Jesus Christ? From Him he received power to baptize whom he afterwards baptized. Do not marvel; for Christ acted in the same manner in respect to John as in respect to His mother. For concerning Christ it was said, “All things were made by Him.” If all things were made by him, Mary also was made by Him, of whom Christ was afterwards born. Give heed, beloved; in the same manner that He did create Mary, and was created by Mary, so did He give the baptism of John, and was baptized by John.
Source: Tractates on the Gospel of John (New Advent)