Hi,
Let's see. I read the link, and it's rather funny and misleading also.
Isaiah 7:14 Therefore the Lord Himself shall give you a sign; Behold, a virgin shall conceive, and bear a son, and shall call his name Immanuel. (KJV)
Let's read:
Isaiah 7:11 Ask thee a sign of the LORD thy God; ask it either in the depth, or in the height above. [12] But Ahaz said, I will not ask, neither will I tempt the LORD. [13] And he said, Hear ye now, O house of David; [Is it] a small thing for you to weary men, but will ye weary my God also? [14] Therefore the Lord Himself shall give you a sign; Behold, a virgin shall conceive, and bear a son, and shall call his name Immanuel. [15] Butter and honey shall he eat, that he may know to refuse the evil, and choose the good. [16] For before the child shall know to refuse the evil, and choose the good, the land that thou abhorrest shall be forsaken of both her kings. (KJV)
Wow, what do we understand from that?
The event is to take place in Ahaz time as you can see clearly when you read the above verses. What sense does it make to offer a sign to Ahaz if it wasn’t going to come to pass within his lifetime?
Here is what other christian bibles translate:
Therefore the Lord himself will give you a sign. Behold, a young woman shall conceive and bear a son, and shall call his name Immanuel. (Revised Standard Version)
Because you do, the Lord of His own accord will give you a sign; it is this: A young woman is with child, and she will give birth to a son and call him Immanuel. (Revised English Bible)
The link you provided was right when it used the word "parthenos" which means "virgin", but they deceive here for the following simple reason:
The Septuagint is the Greece translation of the OT. The Jews only translated the first five books of Moses, BUT the rest was translaled by NON JEWS.
check the following verses please from Isiaih:
Isaiah 23:4 Be thou ashamed, O Zidon: for the sea hath spoken, [even] the strength of the sea, saying, I travail not, nor bring forth children, neither do I nourish up young men, [nor] bring up virgins. (KJV)
[23] And he said, Thou shalt no more rejoice, O thou oppressed virgin, daughter of Zidon: arise, pass over to Chittim; there also shalt thou have no rest. (KJV)
[62] For [as] a young man marrieth a virgin, [so] shall thy sons marry thee: and [as] the bridegroom rejoiceth over the bride, [so] shall thy G-d rejoice over thee. (KJV)
The word "almah" is not used here. The word "be’tulah" is used here instead.
So of course all you can say here is that it's a dual prophecy.
I'll repeat myself again and expose your flawed logic:
If this is a dual prophecy and we are to take your very trusted KJV translation, THEN there existed another virgin before virgin Mary.
And since this is not true, then that word can not mean virgin.