Augustine of Hippo

So far as relates to man in himself, he is of earth, and speaks of the earth; and when he speaks some divine things, he is enlightened by God. For, were he not enlightened, he would be earth speaking of earth. God's grace is apart by itself, the nature of man apart by itself. Do but examine the nature of man: man is born and grows, he learns the customs of men. What does he know but earth, of earth? He speaks the things of men, knows the things of men, minds the things of men; carnal, he judges carnally, conjectures carnally: lo! …

Tractates on the Gospel of John, Tractate 14 ↗

Thomas Aquinas

"For you." Here he turns to prayer, as if to say: so just are you. "For you light my lamp." And he does two things. First he gives thanks for a benefit received. Second, he sets forth a petition for one to be received, at "O my God, enlighten my darkness." He says therefore, "You light," etc. This whole passage can be expounded literally in two ways: so that by "lamp" is understood prosperity, and by "darkness" is understood adversity. …

Exposition on the Psalms of David ↗