So, in order to render the Virgin worthy of this sublime purpose, God marked this ever-virgin Daughter now praised by us, from before the ages, and from eternity, choosing Her from out of His elect.
Turn your attention then, to where this choice began. From the sons of Adam God chose the wondrous Seth, who showed himself a living heaven through his becoming behavior, and through the beauty of his virtues. That is why he was chosen, and from whom the Virgin would blossom as the divinely fitting chariot of God. She was needed to give birth and to summon the earth-born to heavenly sonship. For this reason also all the lineage of Seth were called “sons of God” (Gen. 6), because from this lineage a son of man would be born as the Son of God. The name Seth signifies a rising or resurrection, or more specifically, it signifies the Lord, Who promises and gives immortal life to all who believe in Him.
And how precisely exact is this parallel! Seth was born of Eve, as she herself said, in place of Abel, whom Cain killed through jealousy (Gen. 4:25); and Christ, the Son of the Virgin, was born for us in place of Adam, whom the author of evil also killed through jealousy. But Seth did not resurrect Abel, since he was only a type of the resurrection. But our Lord Jesus Christ resurrected Adam, since He is the very Life and the Resurrection of the earth-born, for whose sake the descendents of Seth are granted divine adoption through hope, and are called the children of God. It was because of this hope that they were called sons of God, as is evident from the one who was first called so, the successor in the choice. This was Enoch, the son of Seth, who as Moses wrote, first hoped to call on the Name of the Lord (Gen. 4:26).
In this manner, the choice of the future Mother of God, beginning with the very sons of Adam and proceeding through all the generations of time, through the Providence of God, passes to the Prophet-King David and the successors of his kingdom and lineage.
— St. Gregory Palamas, Excerpt from Discourse on the Feast of the Entry of the Most Holy Theotokos into the Holy of Holies