Augustine of Hippo
Catena Aurea · Johannesevangelium 6
The Jews then murmured at him, because he said, I am the bread which came down from heaven. And they said, Is not this Jesus, the son of Joseph, whose father and mother we know? how is it then that he saith, I came down from heaven? Jesus therefore answered and said unto them, Murmur not among yourselves. No man can come to me, except the Father which hath sent me draw him: and I will raise him up at the last day. It is written in the prophets, And they shall be all taught of God. Every man therefore that hath heard, and hath learned of the Father, cometh unto me. Not that any man hath seen the Father, save he which is of God, he hath seen the Father.
(de Prædest. Sanctorum, c. viii) Or thus; When a schoolmaster is the only one in a town, we say loosely, This man teaches all here to read; not that all learn of him, but that he teaches all who do learn. And in the same way we say that God teaches all men to come to Christ: not that all do come, but that no one comes in any other way.