David Kimhi (medieval rabbi) critiques the Christian interpretation of almâ as "virgin" in Isaiah 7:14.
David Kimhi, Spr yš’yhw, in Christophe Rico and Peter J. Gentry, The Mother of the Infant King, Isaiah 7:14: ‘almâ and parthenos in the World of the Bible, a Linguistic Perspective (trans. Peter J. Gentry; Eugene, OR: Wipf and Stock, 2020), 171
“hā’almâ—This word does not refer to a virgin as Christians says it does, but to an ‘almâ: a young girl (na’āra) who could be virgin or not. For it is written, ‘the way of a man is an ‘Almâ’ (Pr 30:19). This one was not a virgin. In fact, a very young boy is called an ‘elem (‘who is this ‘elem the son of?” 1 Samuel 17:56). Now this girl was very young, and that is why she is called an ‘almâ. At first glance, this ‘almâ is either the wife of the prophet or the wife of Ahaz. However, it is the second possibility that one must retain here, for if she was he wife of the prophet, one would have written, ‘the prophetess’ as one may read in Is 8:3 (‘I approached the prophetess’). Besides, it is written, ‘the entire extent of your land, Immanuel” (Is 8:8), which shows that the text refers to the king’s son.” (our own translation).