Some there are who have imagined that another origin must be found for the title “Son of man;” for they have had the presumption to call the Father Himself Man, by reason of the profound mystery of this title: so that what can you hope for more ample concerning faith in that God, with whom you are now yourself on a par? Such conceits are constantly cropping out amongst them, from the redundance of their mother’s seed. And so it happens that the doctrines which have grown up amongst the Valentinians have already extended their rank growth to the woods of the Gnostics.
Tertullian
Against the Valentinians
Chapter XXXIX