My take on the matter of the virgin birth is that Matthew intentionally used the Greek
parthenos instead of the Hebrew
almah not because it was already considered a messianic prophecy (it was not) but because it served as part of his effort to solve a problem. The problem was that Paul’s pre-existing divine Christ would sound like polytheism to Matthew’s Jewish Christian community.
Paul had described Christ as the Son of God in the same sense as Philo of Alexandria had used the term, as a pre-existent divine entity serving as mediator between God and the world. Philippians 2 carries the strong sense of Philo’s concept and Colossians 1 is even plainer in describing Christ as the agent whereby the world was created. Philo was himself a Jew and naturally a monotheist. Because of this he jumped through philosophical hoops to transform the Platonic demiurge concept he wanted to import into a ‘not another god’. But to an ordinary Jew, this would be polytheism, the ultimate sin. We might mention at this time that when Paul was speaking to a community partly consisting of Jewish Christians (in Romans) he does not have Jesus become the Son of God until the resurrection, avoiding the issue.
Matthew 1 begins with an elaborate genealogy for Joseph, beginning with Abraham, the first Jew, and virtually avalanching down through David, the ‘got to have’ messianic ancestor and through the line of kings, an important notion for Matthew, and up to Joseph himself. Then Matthew tells us that Jesus is conceived in a virgin by the Holy Spirit. That virgin is betrothed to Joseph but nonetheless Joseph is not the biological father. What good then is that genealogy?
I see Matthew pulling off two tricks here. One is that Jesus seems to come into existence at the point of conception, not coming from heaven but a new being. The polytheism aspect is ameliorated. Jesus is literally the Son of God, an already well-established idea, but not literally divine.
The second trick is more subtle. Paul used Philo to make Jesus divine. Matthew uses Philo to make Jesus human, although a very special human. In Philo’s
The Cherubim, the idea is discussed of God inspiring pregnancies in mortal women as mentioned in the scriptures, at least according to the exegeses of Philo. He even points to an instance of no human agency being involved. And the most worthy recipient of God’s favors, although not in the human manner, would be a virgin. But the clincher is that, since God needs nothing (a big point in Philo’s thinking), the child would truly and legitimately belong to the nominal father.
Here is what Philo says in
The Cherubim
XIII 45 …For he introduces Sarah as conceiving a son when God beheld her by himself; but he represents her as bringing forth her son, not to him who beheld her then, but to him who was eager to attain to wisdom, and his name is called Abraham.
46 And she having conceived, brought forth, not to God, for he alone is sufficient and all-abundant for himself, but to him who underwent labour for the sake of that which is good, namely, for Jacob; so that in this instance virtue received the divine seed from the great Cause of all things, but brought forth her offspring to one of her lovers, who deserved to be preferred to all her other Suitors.
47 Again, when the all-wise Isaac addressed his supplications to God, Rebecca, who is perseverance, became pregnant by the agency of him who received the supplication; but Moses, who received Zipporah, that is to say, winged and sublime virtue, without any supplication or entreaty on his part, found that she conceived by no mortal man.
49 … Sowing for the race of mankind the seed of happiness in good and virgin soil. For it is fitting for God to converse with an unpolluted and untouched and pure nature, in truth and reality virgin, in a different manner from that in which we converse with such.
Jesus is therefore truly and legitimately a ‘Son of David’ – a phrase used often by Matthew – and therefore eligible to be the Jewish Messiah. At the same time, Jesus is the literal Son of God and very special, yet not in the Pauline sense with its intimations of polytheism.
This is why Matthew chose to use the Greek
parthenos instead of the Hebrew
almah. Not a mistake, not a mistranslation. Intentional and purposeful.
The ironic aspect here is that although it is Matthew’s account that first led to the idea of Mary as the Mother of God, it is not an idea that Matthew would have agreed with.