Matthew was the first gospel to add a birth story, probably to answer questions about Mary that persisted in ca 100 A.D. Scholars say that Matthew is the most Jewish of the gospels, so his birth story is told from Joseph’s perspective. And yet, Matthew subtly makes Mary more important than Joseph, to the point of saying that he is not Jesus’ father.
And Jacob begat Joseph the husband of Mary, of whom was born Jesus, who is called Messiah. Matthew 1:16
That is exactly the birth story Matthew fleshed out.
Now the birth of Jesus…was on this wise: When as his mother Mary was espoused to Joseph, before they came together, she was found with child… Matthew 1: 18-19
If Joseph had a Davidic bloodline and had contracted an alliance with a young virgin princess who could bear a contender for the throne…this was a blow…even with her prophecy (See post on The Abuse of the Virgins) that she would be the one to bear such a son…even and especially if the real father was Herodian. Understanding that both Matthew and Luke’s birth stories are quite different, the emphasis in both was put on Mary’s virginity. First, Matthew calls up an old prophecy for a way in the past king that Isaiah tries to cheer up with a prophecy that this particular new young virgin wife (alma) would give bear him a blessed son in the normal fashion:
“Behold, a virgin shall be with child, and shall bring forth a son, and they shall call his name Emmanuel.” (Matthew 1:23)…changed to “And she shall bring forth a son, and thou shalt call his name JESUS…” (Matthew 1:21)…