The first debated point is whether Isaiah was speaking of a virgin at all, for he does not use the Hebrew word which is said to specifically indicate a virgin (bětûlāh) but ‘almāh, which denotes a young woman of marriageable age, who is not necessarily a virgin. Since this young woman conceives and bears, objectors say, she is obviously not a virgin, but a young woman who marries (or is already married), and then conceives and bears a child in the usual way.

In this regard, one can first note that the Septuagint had already translated ‘almāh with parthenos (unambiguously “virgin”) some two hundred years before Christ. It was not Christians who decided that Isaiah is talking about a virgin. Again, ‘almāh is never used in Scripture to describe a married woman, and this in a culture in which a bride found not to be a virgin was liable to stoning (Dt 22:21). This incidentally shows that the ‘almāh could not be the wife of Isaiah or the mother of Hezekiah, as has been argued. Besides the Biblical texts, we have a Ugaritic text which uses the words corresponding to ‘almāh and bětûlāh in parallelism, and thus as synonyms. Furthermore, the contention that bětûlāh is the word for specifically dedicated a virgin has been seriously challenged to the point that it is no longer tenable to affirm that Isaiah would have used bětûlāh if he had meant to speak of a virgin.

Apart from philological considerations, we must also consider the context in which the word appears: if the ‘almāh were not a virgin, but a woman who conceives and bears a child in the usual way, it is hard to see how there could be any sign at all, much less an extraordinary sign of the kind Isaiah offers.

Finally, for a Christian what is decisive is Matthew’s quotation of Isaiah, which clearly asserts that the ‘almāh in whom the prophecy is fulfilled is in fact a virgin. It is therefore somewhat of a moot point for us whether ancient Jewish readers or even Isaiah himself could have understood the ‘almāh as a non-virgin. This is especially the case in the context of this book, where we are concerned with how the prophecy was fulfilled.