Tertullian,
Ante-Nicene Fathers Vol. III, Anti-Marcion…
(1885)
“ Himself, and took upon Him the form of a servant,” not the reality, “and was made in the likeness of man,” not a man, “and was found in fashion as a man,” [9] not in his substance, that is to say, his flesh; just as if to a substance there did not accrue both form and likeness and fashion. It is well for us that in another passage (the apostle) calls Christ “the image of the invisible God.” ”
