Augustine of Hippo — as excerpted in the Catena Aurea on John 6:41-46

“(super Joan. Tr. xxv. 7) All the men of that kingdom shall be taught of God; they shall hear nothing from men: for, though in this world what they hear with the outward ear is from men, yet what they understand is given them from within; from within is light and revelation. I force certain sounds into your ears, but unless He is within to reveal their meaning, how, O ye Jews, can ye acknowledge Me, ye whom the Father hath not taught?”