Also, the line of descent ought to be brought down to Joseph, that in wedlock no wrong might be done to the male sex, as the more worthy, providing only nothing was taken away from the truth; because Mary was of the seed of David.
Hence then we believe that Mary was in the line of David; namely, because we believe the Scripture which affirms two things, both that Christ was of the seed of David according to the flesh, and that He should be conceived of Mary not by knowledge of man, but as yet a virgin.
The Council of Ephesus: Herein we must beware of the error of Nestorius, who thus speaks; “When Divine Scripture is to speak either of the birth of Christ which is of the Virgin Mary, or His death, it is never seen to put God, but either, Christ, or Son, or Lord; since these three are significative of the two natures, sometimes of this, sometimes of that, and sometimes of both this and that together. And here is a testimony to this, ‘Jacob begot Joseph the husband of Mary, of whom was born Jesus, who is called Christ.’ For God the Word needed not a second birth of a woman.”
Reproduced in full. Translation: Oxford 1841 (Newman), public domain (Public domain).