This familiar verse is often mistranslated to say that a virgin will give birth and it is taken by non-Jewish sources as a messianic prophecy. It is not; it was a sign given by Isaiah to King Achaz regarding foreign affairs of the time. Rashi clarifies that the woman in question – Isaiah’s own wife – would conceive and give birth to a son that very year, which was the fourth year of the reign of King Achaz. Furthermore, she would name the child Immanuel of her own volition.