Hebrew had a word that means virgin and means it without ambiguity: בְּתוּלָה (betulah). When a biblical writer wanted to specify that a young woman had not had sexual relations — to make the point precisely and leave no room for the ordinary assumption — betulah was the word available to him. It is the term that carries the specific sense English readers hear in virgin.

This word matters most for what it reveals by its absence. The single most famous virgin-birth prophecy in the Bible — Isaiah 7:14, which Matthew quotes at the opening of his Gospel — does not use betulah. Isaiah used almah, a different word, meaning a young woman of marriageable age. Almah can carry the sense virgin by cultural implication, but it does not specify it the way betulah does. The word that would have nailed the meaning down was sitting in the language, and Isaiah didn’t reach for it.

That contrast is the quiet center of the whole matter. If the Hebrew prophet had wanted to declare unmistakably that a virgin would conceive, the vocabulary was at hand. He could have written betulah. Instead the verse came down through the Hebrew with almah, leaving the question of virginity open rather than asserted. The specifically-virginal reading entered the prophecy later, and from another language: the Septuagint translators in Alexandria rendered almah with the Greek parthenos, which does mean virgin specifically, roughly two centuries before Jesus. Matthew quoted that Greek, and the virgin-birth-as-fulfilled-prophecy argument rests on it.

So betulah functions here almost like a word held in reserve — the precise term Isaiah could have used and did not. Recognizing it doesn’t diminish the doctrine; it sharpens the reader’s hearing of the text. The Hebrew of Isaiah 7:14 is open where the Greek translation is closed, and the difference between the two words, almah and betulah, is exactly the difference between a young woman of marriageable age and a virgin specified as such. The first audience of the Hebrew prophet heard the open word. To know that betulah existed, unused, in the same language is to hear the texture of what was actually said — and to understand how much of the later argument came to rest on a single Greek choice rather than on the word the Hebrew left aside.