“Concerning his Son Jesus Christ our Lord, which was made of the seed of David according to the flesh;”
King James Version (KJV)
1:3 Who was of the seed of David according to the flesh - That is, with regard to his human nature. Both the natures of our Saviour are here mentioned; but the human is mentioned first, because the divine was not manifested in its full evidence till after his resurrection.
Ro 1:3 Concerning his Son. The Son of God is the very center of the gospel, and the promises are all concerning him. Born of the seed of David. The two natures combined in the Son, "according to the flesh", are pointed out in this verse and Ro 1:4. As to his human body, he was a descendant of David (Lu 1:32,69), his mother being of David's lineage (Mt 1:16 Lu 3:23).