"Therefore the Lord himself shall give you a sign; Behold, a virgin shall conceive, and bear a son, and shall call his name Immanuel." [Isiah 7:14]
However, according to SecWeb's A Virgin-Birth Prophecy? [sn] by Kenneth E. Nahigian, the near unanimous opinion of scholars is that this is based on an incorrect translation. The original Masoretic text of Isaiah 7:14 reads:
"Therefore the Lord himself shall give you a sign; Behold, ha'almah shall conceive, and bear a son, and shall call his name Immanuel." [Isaiah 7:14, Masoretic text] [sn]
"Ha'almah" means just "adolescent female". The specific words for "virgin" are
"betulah" or "bethulah". Nahigian also found that (with emphasis added):
"More to the point, nearly all modern commentaries agree with Talmudic scholars that Isaiah's "sign" had nothing to do with a messiah. Reviewing half a dozen for this article, I found only one dissenter. Significantly, it was one that spouted the fundamentalist party line on every other issue. Interested readers can jaunt to the library and peruse the massive Interpreter's Bible (Vol. 5, pp. 217-22), one of the most authoritative works in the field. Or more succinctly, try the popular Harper's Bible Dictionary (Paul J, Achtemeier, gen. ed., 1985), page 419, where this statement is found: 'It is clear, however, that... Isaiah 7:14 did not speak of the miraculous birth of Jesus centuries later.... The sign of Immanuel offered by the prophet to Ahaz had to do with the imminent birth of a child, of a mother known to Ahaz and Isaiah, and signified God's presence with his people...'" [sn]
This analysis is confirmed by The Oxford Companion To The Bible's entry on the "Virgin Birth" (page 790) [ov].
In short, the idea that the Messiah would be born of a virgin does not appear in Jewish lore. Moreover, the story that Jesus Christ was born of a virgin does not appear to have entered Christianity until the time Matthew was written after 70 CE. (It does not, for example, appear in the hypothetical Gospel of Q) [rq].
A reasonable explanation for the confusion comes from the first century Jewish Historian Josephus, who wrote that all but the first five books of the Old Testament were translated into Greek by Gentiles, not Jews:
"I found, therefore, that the second of the Ptolemies was a king who was extraordinarily diligent in what concerned learning and the collection of books; that he was also peculiarly ambitious to procure a translation of our law... into the Greek tongue... for he did not obtain all our writings at that time; but those who were sent to Alexandria as interpreters gave him only the books of the law, while there were a vast number of other matters in our sacred books. [Preface To Antiquities, III]." [jp]
This gives ample room for a misunderstanding the original words of Isiah by later Greek speaking authors of the New Testament [cm].
"And if we even affirm that He was born of a virgin, accept this in common with what you accept of Ferseus." (XXII)
"For by the power of God He was conceived by a virgin of the seed of Jacob, who was the father of Judah, who, as we have shown, was the father of the Jews; and Jesse was His forefather according to the oracle, and He was the son of Jacob and Judah according to lineal descent." (XXXII)
"And when they heard it said by the other prophet Isaiah, that He should be born of a virgin, and by His own means ascend into heaven, they pretended that Perseus was spoken of." (LIV)
However, even pagans from around the time of Justin do not seem to have been impressed. Celsus is said to have written [cv]:
"What an absurdity! Clearly the Christians have used the myths of Danae and the Melanippe, or of the Auge and the Antiope in fabricating the story of Jesus' virgin birth." (p57).
"After all, the old myths of the greeks that attribute a divine birth to Perseus, Amphion, Aeacus and Minos are equally good evidence of their wondrous works on behalf of mankind--and are certainly no less lacking in plausibility than the stories of your followers." (p59).
"The men who fabricated this genealogy [of Jesus] were insistent on the point that Jesus was descended from the first man and from the king of the Jews [David]. The poor carpenter's wife seems not to have known she had such a distinguished bunch of ancestors." (p64).
Despite all this, many Christians do still insist that the virgin birth of Jesus was distinct from the pagan myths which preceded the story. They point out that pagan myths tell of Gods taking the form of men and impregnating women, rather than conception through a "spirit of God" [mr]. However, these objections ignore the apparent mistranslation of the prophecy in Isiah, and still expect us to accept one miraculous account over another - based on a single Gospel account not written until a generation after the supposed time of Christ.
