Ambrose of Milan — as excerpted in the Catena Aurea on Luke 5:17-26

“From the Pharisees themselves therefore the Son of God receives testimony. For it is both more powerful evidence when men confess unwillingly, and a more fatal error when they who deny are left to the consequence of their own assertions. Hence it follows, Who can forgive sins, but God only? Great is the madness of an unbelieving people, who though they have confessed that it is of God alone to forgive sins, believe not God when He forgives sins.”