3 Paul, when writing to the Romans, has explained this very point: “Paul, an apostle of Jesus Christ, predestinated unto the Gospel of God, which He had promised by His prophets in the holy Scriptures, concerning His Son, who was made to Him of the seed of David according to the flesh, who was predestinated the Son of God with power through the Spirit of holiness, by the resurrection from the dead of our Lord Jesus Christ.” And again, writing to the Romans about Israel, he says: “Whose are the fathers, and from whom is Christ according to the flesh, who is God over all, blessed for ever.” And again, in his Epistle to the Galatians, he says: “But when the fullness of time had come, God sent forth His Son, made of a woman, made under the law, to redeem them that were under the law, that we might receive the adoption;” plainly indicating one God, who did by the prophets make promise of the Son, and one Jesus Christ our Lord, who was of the seed of David according to His birth from Mary; and that Jesus Christ was appointed the Son of God with power, according to the Spirit of holiness, by the resurrection from the dead, as being the first begotten in all the creation; the Son of God being made the Son of man, that through Him we may receive the adoption,— humanity sustaining, and receiving, and embracing the Son of God. Wherefore Mark also says: “The beginning of the Gospel of Jesus Christ, the Son of God; as it is written in the prophets.” Knowing one and the same Son of God, Jesus Christ, who was announced by the prophets, who from the fruit of David's body was Emmanuel, “the messenger of great counsel of the Father;” through whom God caused the day-spring and the Just One to arise to the house of David, and raised up for him an horn of salvation, “and established a testimony in Jacob;” as David says when discoursing on the causes of His birth: “And He appointed a law in Israel, that another generation might know [Him,] the children which should he born from these, and they arising shall themselves declare to their children, so that they might set their hope in God, and seek after His commandments.” And again, the angel said, when bringing good tidings to Mary: “He shall he great, and shall be called the Son of the Highest; and the Lord shall give unto Him the throne of His father David;” acknowledging that He who is the Son of the Highest, the same is Himself also the Son of David. And David, knowing by the Spirit the dispensation of the advent of this Person, by which He is supreme over all the living and dead, confessed Him as Lord, sitting on the right hand of the Most High Father.
Source: Adversus haereses (New Advent)