Answers for a Jew
Is Jesus a descendant of David?
Question: How can Jesus be a descendant of David if he is not the son of Joseph by birth?
Answer: This question has to do with the prophecy about the Messiah coming from the tribe of Judah: «The sceptre shall not depart from Judah, nor a lawgiver from between his feet, until Shiloh [Peacemaker] come; and unto him shall the gathering of the people be» (Gen 49:10; compare 1 Kings 2:4; Ps 132:11).
According to the Gospels, Jesus was conceived by Mary through the Holy Spirit, and Joseph (from the tribe of Judah – David's line) was not his father according to the flesh. Concerning Mary's genealogy, the Holy Tradition teaches: her parents, Joachim and Anna, were from the tribes of Judah and Levi, respectively. The Gospel of Luke mentions Mary's relative Elizabeth, who was «from the line of Aaron» (Lk 1:5, 36), that is from the tribe of Levi.
Mary's relation to the tribe of Judah is further substantiated by the following considerations. When Ceasar Augustus announced a census «all went to be taxed, every one into his own city. And Joseph also went up from Galilee, out of the city of Nazareth, into Judaea, unto the city of David, which is called Bethlehem; (because he was of the house and lineage of David:) To be taxed with Mary his espoused wife, being great with child» (Lk 2:3-5).
Mary, as the only daughter, was required by the Law to get married: «And every daughter, that possesseth an inheritance in any tribe of the children of Israel, shall be wife unto one of the family of the tribe of her father, that the children of Israel may enjoy every man the inheritance of his fathers. Neither shall the inheritance remove from one tribe to another tribe; but every one of the tribes of the children of Israel shall keep himself to his own inheritance» (Num 36:8-9). That is why Mary was engaged to Joseph who was also from the tribe of Judah.
At the time of the census, Mary wasn't Joseph's wife; they were «pledged to be married» [ἐμνηστευμένῃ αὐτῷ] (Lk 2:5). That's why she had to show up for the census as the only heiress to her parents' property.
So, Jesus, the son of Mary, was «from the seed of David according to the flesh» (Rom 1:3; see Rev 5:5; 22:16).
(to be continued)