Matthew 12:18

The prophet celebrates His meekness, and His unspeakable power, and opens to the Gentiles "a great door and effectual;" he foretells also the ills that are to overtake the Jews, and signifies His unanimity with the Father. For "behold," saith He, "my servant, whom I have chosen, my beloved, in whom my soul is well pleased." Now if He chose Him, not as an adversary doth Christ set aside the law, nor as being an enemy of the lawgiver, but as having the same mind with Him, and the same objects. Then, to inform thee that this too is according to the purpose of the Father, in the beginning the prophet had assured us of this likewise, together with what had gone before; saying, "My well-beloved, in whom my soul is well pleased." For of the well-beloved it is quite evident that He did these things also according to the mind of the beloved.

But the Holy Spirit is put, not on the Word of God, but on the Only-Begotten, who came forth from the bosom of the Father; on Him, that is, of whom it is said, Behold my servant. And what He will do by Him He adds, And he shall declare judgment to the Gentiles.

(De Civ. Dei, xx. 30.) Seeing He preached the judgment to come which was hidden from the Gentiles.

The Lord Jesus Christ is called the servant of the Almighty God, not in respect of His divinity, but in respect of the dispensation of the flesh which He took upon Him, because by the cooperation of the Holy Spirit He took flesh of the Virgin without stain of sin. Some books have, Elect, whom I have chosen, for He was chosen by God the Father, that is, predestinated that He should be the Son of God, proper, not adopted. That he says, My soul, is not to be understood as though God the Father had a soul, but by way of adaptation, showing how God is disposed towards Him. And it is no wonder that a soul is ascribed to God in this manner, seeing that all other members of the body are likewise. Then also God the Father put His Spirit upon Him, when by the working of the Holy Spirit He took flesh of the Virgin; and as soon as He became man, He took the fulness of the Holy Spirit.

Whom I have chosen, he says, for a work which none else has done, that He should redeem the human race, and make peace between God and the world. It follows, My beloved, in whom my soul is well pleased, for He alone is the Lamb without spot of sin, of whom the Father speaks, This is my beloved Son, in whom I am well pleased. (Mat. 17:5)