Matthew 1:23 was correct in interpreting Isaiah 7:14, a virgin birth text.

"Therefore, the Master Himself shall give you a sign [oth]; Behold, a VIRGIN [alma] shall conceive, and bear a son, and shall call his name Immanuel {trans. as 'G-D with us"}."

As we know, in the tanakh, the word "alma" appears 7 times. In Gematria, we are made aware of this, as it teaches us about the character of G-D, whose "being" is comprised also of 7 spirits (Zechariah 4:10) seen as ehad (Zechariah 4:2). This tells us that we are to approach this textual criticism with caution.

The primary contention of the Hasidim to alma being taken as "virgin" in the Tenach, deals primarily with the usage in Proverbs 30:18-20. The way of a man with a young woman or "b'alma" is compared to three things: an eagle in the heavens, the path of a serpent upon the rock, and the course of a ship in the middle of the ocean. In each case, the "way" is the wide course of "derek", which is subject to the whims of the wind and the eagle, the serpent and the slope of the rock, and the ship's master and the motion of the wind and the sea. However, this subject is merely smoke and mirrors for the novice, is it not?

The crux of the matter of Proverbs 30 rests in verse 20, in which the woman performs a "Monica Lewinski" with her mouth, and because her hymen is intact and never violated, she says..."I have done no wickedness", as she wipes the "seed" from her mouth. This is the harshness of the text. Therefore, those doctors of the Law who are called to examine the girl, find her hymen intact, and rule, "SHE IS STILL A VIRGIN."

Therefore, we must again ask ourselves, what activity violates a girl or young woman, so that she is no longer a virgin; and was that act (respecting alma) performed in Proverbs 30:20 or any where else in Scripture? The answer is "no". If we were to argue that "parthenos" is used in the Septuagint in relation to Genesis 32:4, we find that we are discussing a translation of na'arah, not alma.

I find it hypocritical that in order to refute the virgin intent of Almah, that counter-missionaries call Rebekkah a 3 or 13 year old slut (depending on receiving Rashi's lacunae age) as well as Moses' own 12 year old sister, Miriam. So Israel's matrons were sluts so they can refute Yeshua? Pork baloney.
In regards to this "alma", we find that the one who shall be born of her is an "oth". He is a signal, a banner, a miracle that is to come in the distant future. This "oth" is attached upon the lineage of Ahaz (Achaz in Matthew 1:9 in the KJV), and in Isaiah 7:14, v'qarath Shemo Imanu El - "she will call out and address His name [by the familiar -- which means] with rest, home, and pasture (to all who believe), G-D (dwells)."

Rashi expounds that the "almah" teaches of the Shekinah resting upon her, and that our "rock" or "eben" [ the Alef- BeN / trans. as "G-D's Son" in Gematriac analysis] will be with us. Who is our "rock" but HASHEM Himself, I ask? Now if the Hebraic "alma" is true as "virgin" in the Tenach, each and every time, even if the Greek word "parthenos" isn't; there is still no contention for anyone to dispute that in Isaiah 7:14 that the intent of that passage is that of a virgin.

I suggest that you look to another prophetical passage for the answer to Isaiah 7:14, in Jeremiah 22:29-30.
"O eretz, eretz, eretz! Hear and obey the Word of HASHEM! This, is what HASHEM commands: inscribe (in you) this man as a watcher*of*the*irrigation*water*that*slakes*the*thirst*; the Mistress (shall) not push forward to come in the heat of his days. A burning brand which shall not be pushed forward from his posterity, a (First) Man who sits down (to Judge) on the throne of David, and rules with dominion, and rules and rules from Judah." (fully amplified translation from Hebrew, mine)

The three eretz uses focus from Heaven to all the earth, then to the dominion of Abraham, then to the borders of Israel west of the Jordan; and is used as a response to why Jehoichin's rejection (cf. Jeremiah 22:28).

Instead of going back to Deuteronomy 28, and Jeremiah's citation of the worship and incense to "the queen of Heaven", (to which some hasidim sing to at or around Pesach in America) as if G-D had a harlot mistress named Asherah -- instead, the mercy of G-D says that the focus is to be on the posterity of David.

That is, for David's sake, and for HASHEM's own Name's sake, Jehoichin might live to bring forth a descendant who is NOT Messhaich, but a watcher over "he who possesses the aoinios or life-force of eternity" as "living waters"...i.e., HASHEM [cf. Jeremiah 2:13, 17:13; Ezekiel 47:1].

This "watcher", who comes into being after Jehoichin is long dead and buried, is Joseph, the husband of the "alma" called Miriam (Matthew 1:12-16), in 14 generations.

In Micah 5:2, we read that the "comings forth" as umootsata(y)v" is as the source going forth, as though referring to a well spring which origin is unseen, and practically unknowable except in generality. (Cf. Isaiah 12:3-4 in Hebrew, His name is Yeshua, and you will praise his name and works among the peoples).

That origin is M'Qedem memey olam...from before the days of eternity, from before the days of the world.

The anti-Christian rabbis argue EleM (Ayin-Lamed-Mem)/ "young man" has the three root letters of ALMaH (Ayin-Lamed-Mem-He), and therefore removes virginity. That argument won't wash. ELeM or "young man" has the same spelling as OLaM (Ayin-Lamed-Mem), eternity / world.
The angels are of an eternal substance, and when men tried to rape two "young man angels" visiting Lot in Sodom, G-D blinded the wicked men of the town or city and destroyed Sodom. Yeshua said that the angels have NO sexual relations in Heaven, they do not marry. Nor will people in the Resurrection marry, or have any sexual relations...they just won't. Therefore, in the application of a prophetical ALMaH, the virgin birth through the word "ALMaH", must be viewed as from OLaM (Ayin-Lamed-Mem) with a letter "He" on the end of it. The interpretation then, signifying in Gematriac analysis, "a revelation of the Spirit by the word of promise", or a Gematriac interpretation to this effect. In other words, something akin to the virgin birth promise made in Isaiah 7:14 by the prophecy of the Holy Spirit of G-D.

In Isaiah 7:14, we have "The Virgin" or Ha Almah that is given "to you" in the plural. That is, if "to You" was in the singular, we might concede that it could mean Ahaz...but since Ahaz was not beside himself as a set of twins or triplets to rule the throne as one man, the pluralized "to you" which immediately precedes HaAlmah, is addressing all of the House of Judah in the the prophecy.

G-D will spring forth like a stream or a well-spring which is drawn from the midst of the virgin (again, Isaiah 12:2,3 names Him as Yeshua), and be born among men by the power of the Holy Spirit by a source and means hidden from the understanding of man... except in generalities.

For this reason, Almah, which speaks of a "hiddenness", was chosen. Lest perhaps, someone would say of Deuteronomy 22:19 that in Moses' Torah, it speaks of a Bethulah as one having already had intercourse, and that this would have been the hidden meaning of Isaiah 7:14 if Bethulah would have been handed down to us in the prophecy, instead of Almah.

And if G-D raised Isaac from the dead, after that his heart was pierced by the knife of Abraham and stopped its beating upon the wood...as Paul indicates through Luke in Hebrews 11:17-19...from where did the well-spring of resurrection life come forth, but from within, because of a trusting faith into G-D upon His promises when G-D himself called for it? Isaac, therefore, was a type of the Christ who was to come...innocent, sacrificed, and who rose from the dead after paying the obligations of another.

In Esther 2:17 and Joel 1:8, it cannot be categorically stated that Bethulah means a virgin, and appears to show cause to believe "almah" is the better translation regarding Biblical use in the OT texts.

Cyrus Gordon in Journal of Bible and Religion’s 21:240-241 argued that the origins of Bethulah in the near eastern languages does not meet the virgo intacta demands the anti-Almah contenders say that Bethulah would have carried.

In the Akkadian, the related Bethulah cognate will only translate to virginity when applied to the very youthful;
{the Assyrian Dictionary Volume 2, University of Chicago, 1965, pp. 173-174 regarding "batultu" (pp. 192-193 on pdf. scroll)

http://oi.uchicago.edu/pdf/cad_b.pdf }

while in the Ugaritic, the possible root "btlt" is a oft a reference to the wife of Baal, who indeed has an active sex life in the mythology regarding Baal and Anat. Had bethulah been used, the prophecy could not have definitively meant a "virgin" while Almah could so be used.