Et chatai ani mazkir hayom. The truth of the mistranslation is not so black and white. What actually occurred is messier, and tells us something interesting, I think, about the role of midrash
First, things first, it wasn't the church who did the translating. The translation of the word almah to virgin was known to Mathew, and Mathew was years before the establishment of any church. Second, the translation wasn't the work of Christians or Jewish-Christians. It appears in the Septuagint, the book Jewish tradition says was the work of 70 (or 72 or 5) rabbis, and history tells us was sort of the ArtScroll Chumash of Jewish communities in the Greek diaspora. According to Kugel, its likely the translators took almah as virgin -- not that they expected that a virgin would conceive, but that a virgin would get married and have a child in the ordinary way.
Hundreds of years later, with only the Greek translation in his hands, Mathew read the verse in Issiah as follows:
All this took place to fulfill what the Lord had said through the prophet: "The virgin will be with child and will give birth to a son, and they will call him Immanuel"—which means, "God with us." - Mat 1:18As noted by Raymond Brown, and others, Mathew either had a variant, or made three deliberate changes to the LXX:
(1) He read en gastri lepsetai [lit., "will receive in the womb"] as en gastri hexei [lit., "will have in the womb"] a subtle change, but one Brown says changes the prophecy into an imminent or future one
(2) He made vkarat, the singular "he will call", into "they will call"; and
(3) He glosses Immanuel as "God with us" that is, he tells us what the name means, rather than what the living child is meant to represent.
The significance of all this? Issiah's original prophecy was delivered to King Ahaz, and per the context seems intended as a guarantee to the King that he and his Kingdom will survive an Assyrian attack. Some six hundred years later, Mathew reads it differently. To him, the prophesy was not immediately fulfilled, has relevance to all Israel (they will call him) and the name of the child has special significance. In the original sense, the name seems to be a sign that "God in our midst" that is He is in the Temple, protecting us. To Mathew writing at the sour end of the Second Temple era --possibly, even after it was destroyed -- the name refers to the child himself, and means that God is now with us in the person of the child, that is the person of Jesus.
The violence done to the verse was not committed by the church, or by a Christian, but by the first century Jew who wrote Mathew (or his source/teacher). This, I think, makes all the difference in the world, and here I come to my point.
Mathew, by virtue of his time and place, probably had the sensibilities of a baal midrash and he probably used a similar approach. Like the authors of the canonical midrashim, he approached the Torah with certain assumptions, particularly: The Torah is (1) God's word, and the texts are (2) cryptic (3) symbolic (4) prophetic and (5) homiletic. And like the canonical midrash writers who functioned at the very end of the Second Temple Era, Mathew looked to the Torah for some clue that the bitterness of Roman rule would be removed, that God's old promises would be fulfilled, and that redemption was imminent; most importantly he searched for some indication that Israel had not been abandoned.
Mathew found all of this in the person and teaching of Jesus, which is why his writings aren't part of our tradition, but he justified his discovery, in part, through his drasha on Iss 7:14, a drash that does do violence to the original meaning of a passage, but quite honestly no more or less than the violence done to original meaning by many of the midrashim we wholeheartedly accept. [For an example see Rabbi Akiva's homily on teshuva, a drash from around the same time and place, that attempts to answer the same fundamental question Mathew answers, through the use of a pun on the word mikva. Rabbi Akiva changes the meaning of his passage, just as Mathew changes the meaning of his passage.] There's nothing unusual about a midrash that relies on subtle and not so subtle changes to a passage's original meaning - we're so used to it, we often miss it - and that's all Mathew did here.
Jews, of course, reject Mathew's book, together with his savior and his drasha. My objective here is not to argue for the rehabilitation of any of them. This is just something I thought was interesting....
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