ist's father, as shown above
(Q. 28, A. 1, ad 1, 2). Therefore it seems that Christ was not
descended from David.

Obj. 2: Further, Aaron was of the tribe of Levi, as related Ex. 6.
Now Mary the Mother of Christ is called the cousin of Elizabeth, who
was a daughter of Aaron, as is clear from Luke 1:5, 36. Therefore,
since David was of the tribe of Juda, as is shown Matt. 1, it seems
that Christ was not descended from David.

Obj. 3: Further, it is written of Jechonias (Jer. 22:30): "Write this
man barren . . . for there shall not be a man of his seed that shall
sit upon the throne of David." Whereas of Christ it is written (Isa.
9:7): "He shall sit upon the throne of David." Therefore Christ was
not of the seed of Jechonias: nor, consequently, of the family of
David, since Matthew traces the genealogy from David through
Jechonias.

_On the contrary,_ It is written (Rom. 1:3): "Who was made to him of
the seed of David according to the flesh."

_I answer that,_ Christ is said to have been the son especially of
two of the patriarchs, Abraham and David, as is clear from Matt. 1:1.
There are many reasons for this. First to these especially was the
promise made concerning Christ. For it was said to Abraham (Gen.
22:18): "In thy seed shall all the nations of the earth be blessed":
which words the Apostle expounds of Christ (Gal. 3:16): "To Abraham
were the promises made and to his seed. He saith not, 'And to his
seeds' as of many; but as of one, 'And to thy seed,' which is
Christ." And to David it was said (Ps. 131:11): "Of the fruit of thy
womb I will set upon thy throne." Wherefore the Jewish people,
receiving Him with kingly honor, said (Matt. 21:9): "Hosanna to the
Son of David."

A second reason is because Christ was to be king, prophet, and
priest. Now Abraham was a priest; which is clear from the Lord saying
unto him (Gen. 15:9): "Take thee [Vulg.: 'Me'] a cow of three years
old," etc. He was also a prophet, according to Gen. 20:7: "He is a
prophet; and he shall pray for thee." Lastly David was both king and
prophet.

A third reason is because circumcision had its beginning in Abraham:
while in David God's election was most clearly made manifest,
according to 1 Kings 13:14: "The Lord hath sought Him a man according
to His own heart." And consequently Christ is called in a most
special way the Son of both, in order to show that He came for the
salvation both of the circumcised and of the elect among the Gentiles