[AlguyA]

'Isaiah 7:14, but from the Septuagint, not the Hebrew. The Hebrew word used in this verse is almah, which means "young woman". The Septuagint interprets this in its translation when it renders almah as parthenos. Many modern English translations rely on the Hebrew original and go with "young woman" instead of "virgin"."

Hmm, interesting. But, then, if I'm to be a good Berean as many might suggest I should be, then I better have the Septuagint handy when I sit down to read Matthew because if I have the original Hebrew, then I won't find the scripture to which Matthew is referring and I'm virtually honor-bound then to throw the Gospel out, aren't I?

Also, isn't the Septuagint that version of what Christians call the Old Testament which has all those books in it which Catholics added to the Bible?

[malakhi]

and I'm virtually honor-bound then to throw the Gospel out, aren't I?

I don't think I'm the right person of whom to ask that question. ;o)

Also, isn't the Septuagint that version of what Christians call the Old Testament which has all those books in it which Catholics added to the Bible?

I don't think there is a definitive answer to this. It really isn't accurate to speak of "the Septuagint" as one, bound, definitive text.