
Gregory the Great
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.
(Hom. in Ev. vii. 3.) John baptizes not with the Spirit but with water, because he had no power to forgive sins; he washes the body with water, but not at the same time the soul with pardon of sin.