>Isaiah 7:14 (original Hebrew):יד לָכֵן יִתֵּן אֲדֹנָי הוּא, לָכֶם–אוֹת: הִנֵּה הָעַלְמָה, הָרָה וְיֹלֶדֶת בֵּן, וְקָרָאת שְׁמוֹ, עִמָּנוּ אֵל
>Isaiah 7:14 (Septuagint): διὰ τοῦτο δώσει κύριος αὐτὸς ὑμῖν σημεῖον ἰδοὺ ἡ παρθένος ἐν γαστρὶ ἕξει καὶ τέξεται υἱόν καὶ καλέσεις τὸ ὄνομα αὐτοῦ Εμμανουηλ
>Isaiah 7:14 (Vulgate): propter hoc dabit Dominus ipse vobis signum ecce virgo concipiet et pariet filium et vocabitis nomen eius Emmanuhel.
>Isaiah 7:14 (KJV): Therefore the Lord himself shall give you a sign; Behold, a virgin shall conceive, and bear a son, and shall call his name Immanuel.
A lot of people Jews have criticized the Greek, Latin, and English forms of this verse for saying "παρθένος," "virgo," or "virgin," saying that Christians invented that interpretation of that verse in order to give Jesus an extra "miracle." If you read this verse in the Jewish Publication Society translation of the Tanakh, they translate it
>Therefore, the Lord, of His own, shall give you a sign; behold, the young woman is with child, and she shall bear a son, and she shall call his name Immanuel.
Many Jews use this to argue against Christianity, and many Catholics use this to argue against translating Bibles out of the Hebrew (arguing instead for the Latin or Greek, which were themselves translated out of the Hebrew). https://outreachjudaism.org/alma-virgin/ In this article, a Rabbi argues that Almah means young woman, and that Christians mistranslated that verse intentionally.
This is all bunk. almah is a word with multiple meanings, and there are reasons for it to mean virgin in certain usages, including and especially in Isaiah 7:14. Here's a copy of an academic paper that argues for why almah means virgin in Isaiah 7:14
>The etymological meaning of almah is a sexually mature girl. Most of the argument for the point that
almah also means a married woman is based on etymology. This is the basis when anyone says almah means “virgin and non-virgin,” “unmarried and even married” and adds “whether biblical examples can be supplied or not is beside the point.” and when a commentator is praised for “sticking to ‘meaning’ (of word) rather than making concessions to ‘usage.’” But—
>1. Sound exegesis does not base the meaning of a word on its etymology. When a member of our class in Messianic Prophecies argued for the etymological meaning of almah, our Korean, Mr. Oh, asked him, “You say ‘teaspoon.’ Do you drink tea with it?”
>In exegesis we use etymology only as a makeshift in emergencies where usage fails to help us establish a meaning. Etymology and context is all we have to define a hapaxlegomenon. And sometimes we have to resort to etymological meaning when all the available usage fails to give us a satisfactory meaning in a given context. But almah is not an hapaxlegomenon; and there is sufficient usage to establish its meaning in Is 7:14.
>2. The etymology of almah in no way suggests or proves that it means also a married woman. A trained soldier doesn’t mean war. A sexually mature girl doesn’t imply sex relations. The etymology of almah implies a mature virgin and no more.
The paper continues on with every usage of "almah" in the Old Testament and explains why almah means virgin. This is an important thing for every Christian apologist to know, because otherwise we can be tricked by false translations and Jewish scholars. I'm putting the full pdf here so you can read it, I hope this is found to be helpful and edifying for anyone who argues with religious Jews, anyone who has encountered this claim, or is doubting their own faith.
God bless