Augustine of Hippo
Catena Aurea · Johannesevangelium 12
But though he had done so many miracles before them, yet they believed not on him: That the saying of Esaias the prophet might be fulfilled, which he spake, Lord, who hath believed our report? and to whom hath the arm of the Lord been revealed? Therefore they could not believe, because that Esaias said again, He hath blinded their eyes, and hardened their heart; that they should not see with their eyes, nor understand with their heart, and be converted, and I should heal them. These things said Esaias, when he saw his glory, and spake of him. Nevertheless among the chief rulers also many believed on him; but because of the Pharisees they did not confess him, lest they should be put out of the synagogue: For they loved the praise of men more than the praise of God.
(Tr. liii. 2) It is evident here that the arm of the Lord is the Son of God Himself. Not that the Father has a human fleshly form; He is called the arm of the Lord, because all things were made by Him. If a man had power of such a kind, as that without any motion of his body, what he said was forthwith done, the word of that man would be his arm. Here is no ground to justify, however, the error of those who say that the Godhead is one Person only, because the Son is the arm of the Father, and a man and his arm are not two persons, but one. These men do not understand, that the commonest things require to be explained often by applying language to them taken from other things in which there happens to be a likeness, [cand that, when we are upon things incomprehensible, and which cannot be described as they actually are, this is much more necessary. Thus one man calls another man, whom he makes great use of,his arm; and talks of having lost his arm, of having his arm taken away from him.] But some mutter, and ask, What fault was it of the Jews, if it was necessary that the sayings of Esaias should be fulfilled? We answer, that God, foreseeing the future, predicted by the Prophet the unbelief of the Jews, but did not cause it. God does not compel men to sin, because He knows they will sin. He foreknows their sins, not His own. The Jews committed the sin, which He who knows all things foretold they would commit.