Augustine of Hippo
Catena Aurea · Johannesevangelium 1
That was the true Light which lighteth every man that cometh into the world.
(Tract. ii. in Joh. §. 7) Wherefore is there added, true? Because man enlightened is called light, but the true Light is that which lightens. For our eyes are called lights, and yet, without a lamp at night, or the sun by day, these lights are open to no purpose. Wherefore he adds: which lighteneth every man: but if every man, then John himself. He Himself then enlightened the person, by whom He wished Himself to be pointed out. And just as we may often, from the reflexion of the sun’s rays on some object, know the sun to be risen, though we cannot look at the sun itself; as even feeble eyes can look at an illuminated wall, or some object of that kind: even so, those to whom Christ came, being too weak to behold Him, He threw His rays upon John; John confessed the illumination, and so the Illuminator Himself was discovered. It is said, that cometh into the world. Had man not departed from Him, he had not had to be enlightened; but therefore is he to be here enlightened, because he departed thence, when he might have been enlightened.