Reply Obj. 2: Gregory of Nazianzum answers this objection by saying that it happened by God's will, that the royal family was united to the priestly race, so that Christ, who is both king and priest, should be born of both according to the flesh. Wherefore Aaron, who was the first priest according to the Law, married a wife of the tribe of Juda, Elizabeth, daughter of Aminadab. It is therefore possible that Elizabeth's father married a wife of the family of David, through whom the Blessed Virgin Mary, who was of the family of David, would be a cousin of Elizabeth. Or conversely, and with greater likelihood, that the Blessed Mary's father, who was of the family of David, married a wife of the family of Aaron.
Again, it may be said with Augustine (Contra Faust. xxii) that if Joachim, Mary's father, was of the family of Aaron (as the heretic Faustus pretended to prove from certain apocryphal writings), then we must believe that Joachim's mother, or else his wife, was of the family of David, so long as we say that Mary was in some way descended from David.
Reply Obj. 3: As Ambrose says on Luke 3:25, this prophetical passage does not deny that a posterity will be born of the seed of Jechonias. And so Christ is of his seed. Neither is the fact that Christ reigned contrary to prophecy, for He did not reign with worldly honor; since He declared: "My kingdom is not of this world." _______________________
THIRD ARTICLE [III, Q. 31, Art. 3]
Whether Christ's Genealogy Is Suitably Traced by the Evangelists?
Objection 1: It would seem that Christ's genealogy is not suitably traced by the Evangelists. For it is written (Isa. 53:8): "Who shall declare His generation?" Therefore Christ's genealogy should not have been set down.
Obj. 2: Further, one man cannot possibly have two fathers. But
Matthew says that "Jacob begot Joseph, the husband of Mary": whereas
Luke says that Joseph was the son of Heli. Therefore they contradict
one another.
Obj. 3: Further, there seem to be divergencies between them on several points. For Matthew, at the commencement of his book, beginning from Abraham and coming down to Joseph, enumerates forty-two generations. Whereas Luke sets down Christ's genealogy after His Baptism, and beginning from Christ traces the series of generations back to God, counting in all seventy-seven generations, the first and last included. It seems therefore that their accounts of Christ's genealogy do not agree.
Obj. 4: Further, we read (4 Kings 8:24) that Joram begot Ochozias, who was succeeded by his son Joas: who was succeeded by his son Amasius: after whom reigned his son Azarias, called Ozias; who was succeeded by his son Joathan. But Matthew says that Joram begot Ozias. Therefore it seems that his account of Christ's genealogy is unsuitable, since he omits three kings in the middle thereof.
Obj. 5: Further, all those who are mentioned in Christ's genealogy had both a father and a mother, and many of them had brothers also. Now in Christ's genealogy Matthew mentions only three mothers—namely, Thamar, Ruth, and the wife of Urias. He also mentions the brothers of Judas and Jechonias, and also Phares and Zara. But Luke mentions none of these. Therefore the evangelists seem to have described the genealogy of Christ in an unsuitable manner.