Acts 2:34

And that God the Father of all would bring Christ to heaven after He had raised Him from the dead, and would keep Him there until He has subdued His enemies the devils, and until the number of those who are foreknown by Him as good and virtuous is complete, on whose account He has still delayed the consummation-hear what was said by the prophet David. These are his words: "The Lord said unto My Lord, Sit Thou at My right hand, until I make Thine enemies Thy footstool. The Lord shall send to Thee the rod of power out of Jerusalem; and rule Thou in the midst of Thine enemies. With Thee is the government in the day of Thy power, in the beauties of Thy saints: from the womb of morning have I begotten Thee." That which he says, "He shall send to Thee the rod of power out of Jerusalem," is predictive of the mighty, word, which His apostles, going forth from Jerusalem, preached everywhere; and though death is decreed against those who teach or at all confess the name of Christ, we everywhere both embrace and teach it. And if you also read these words in a hostile spirit, ye can do no more, as I said before, than kill us; which indeed does no harm to us, but to you and all who unjustly hate us, and do not repent, brings eternal punishment by fire.

And at Pentecost so as to presignify the kingdom of heaven as He Himself first ascended to heaven and brought man as a gift to God.

Henceforth after the mention of His giving the Spirit, he confidently speaks also of His ascension into heaven; and not only so, but again adducing the witness, and reminding them of that Person concerning Whom Christ once spake. "For not David," says he "ascended into the heavens." Here he no longer speaks in lowly phrase, having the confidence which results from the things said nor does he say, "Be it permitted me to speak," or the like: "But he saith himself; The Lord said unto my Lord, Sit Thou on My right hand, until I make Thine enemies Thy footstool." Now if He be David's Lord, much more shall they not disdain Him. "Sit thou on My right hand;" he has set the whole matter here; "until I make Thine enemies Thy footstool:" here also he has brought upon them a great terror, just as in the beginning he showed what He does to His friends, what to his enemies. And again, as to the act of subjugation, not to provoke unbelief, he ascribes it to the Father.

The Savior has revealed the meaning of these words in the Gospel when He asked: 'If the Christ is the Son of David, how then does David in the Spirit call him Lord? (Mt. 22:43)' The Lord was interrogating the Pharisees because they were acknowledging Christ simply as the son of David.

We know that Christ took his seat at the right hand of the Father after his resurrection from the dead and his ascension into heaven. It is already accomplished. We do not see it, yet we believe it. We have read it in the sacred Books, we have heard it preached, we hold it by faith. And by the very fact that he was the son of David, he has become David's Lord. That which was born of David's seed is so honored that he is also David's Lord. You wonder at this as if such things did not happen in human affairs. For if it should happen that someone became king, though his father was a commoner, would he not be the lord of his father? It is wonderful that it can happen: not only does the son of a commoner become king and thus the lord of his father, but the son of a layman becomes a bishop and thus the father of his father. Therefore, by the very fact that Christ took on flesh, that in the flesh he died, that in the same flesh he rose again, and in the same flesh he ascended into heaven and sits at the right hand of the Father, and in the same flesh now so honored and glorified, transformed into a heavenly condition, he is still the son of David and also the Lord of David.

The words "Sit on my right hand" he speaks as to man, for they are not spoken to him that sits ever on the throne of glory, God the Word after his ascension from earth, but they are said to him who has now been exalted to the heavenly glory as man, as the apostles say, "for David is not ascended into the heavens, but he himself says that the Lord said to my Lord 'Sit on my right hand.' " The order is human, giving a beginning to the sitting; but it is a divine dignity to sit together with God "to whom thousand thousands minister and before whom ten thousand times ten thousand stand."

He no longer speaks with withdrawal. For from what has been said he has confidence. But what does he say? That David says: "The Lord said to my Lord," and therefore shows him higher than David. And if David calls him Lord, much more will they not refuse him.

For David did not ascend into the heavens, but he himself says: The Lord said to my Lord, sit at my right hand. Certain codices have 'The Lord says,' but Greek exemplars in both this book and the Psalter have 'The Lord said.' Most clearly, blessed Peter explains through this psalm how to understand what he previously assumed from another psalm, that the Lord swore to David to raise Christ from the fruit of his loins and to set him on his throne, namely, because this throne of the kingdom is not to be understood in earthly Jerusalem where David reigned, but at the right hand of His majesty in the heavens. Here he evidently asserts both natures of our one Redeemer from the prophetic scriptures: the human, from the fruit of David's loins through the virgin, and the divine because ascending into heaven, the man was received at the right hand of the Father. In this truly, He is the son of David, in that He is the Lord of David, for which reason he congruously added:

For David did not ascend into the heavens. He himself says: "For these latter things, blessed David predicted, not about himself, but about his Lord's ascension, who would be sent forth from Zion, that is, from David's royal lineage, and would rule in the midst of his enemies;" so also understand those previous things he mentioned, which pertain not to David, but to Christ's death and resurrection.

The Lord said to my Lord, "Sit at my right hand." The first name of the Lord among the Hebrews is the Tetragrammaton, which is properly used for God; the second, which is common to mortals, is that by which both kings and other men are called. If the Arian heresy wishes to oppose us with this difference, making the Son lesser, and the Father greater, we will respond that the inferior name belongs to him to whom it is commanded to sit. As blessed Peter explained: "For God made Him both Lord and Christ, this Jesus whom you crucified." For it was not the divinity that was crucified, but the flesh. And this indeed can be done, which could be crucified.

"He himself says: 'The Lord said to my Lord…'" Here Peter speaks already without fear, since what was said above emboldened him. But what is the meaning of the words "The Lord said to my Lord!"? If David himself calls Him (Jesus) Lord, then all the more the Jews should not deny this. In the words "Sit at My right hand" we perceive the equal honor of the Father and the Son, since the concepts of "right" or "left" are inconceivable in relation to an incorporeal essence.