What was the Hebrew text at the time of Jesus - Pshitta along side with the Septuagint? How do we know and how can we trust that the last 2000years since christianity came into the picture that OT - "Septuagint" which the Orthodox church uses has not been tampered to suit us Christians in verses about the Messiah , ie: Isaiah 7:14 - In a nutshell which bible is the inspired word of God to this day ?
The Jews started making new translations, as the Christians proved too good at proving Jesus was the Christ from the LXX.
One of these translations, Theodotion, a Jewish proselyte, produced a new translation meant for Jewish use (his contemporary, St. Irenaeus, notes his and Aquilla of Pontus, another Jewish proselyte translator, of their objection to that very translation of Isaish 7:14, showing that the translation by the LXX predates the Christians use of it). These were produced in reaction to the success of the Christians using the LXX, as shown earlier () in St. Justin martyr's debate with Trypho the Jew.
Reading the Old Testament With the Ancient Church: Exploring the Formation ...
By Ronald E. Heinehttp://books.google.com/books?id=7cSua5-tLIgC&pg=PA117&lpg=PA117&dq=Trypho+Isaiah+7:14&source=bl&ots=Zpgd7a0oOY&sig=U6TEgaMw9lWuoPjm_NT8kcj00Co&hl=en&sa=X&ei=8PjIT6P_Nemw2wXi383aCw&ved=0CFsQ6AEwBw#v=onepage&q=Trypho%20Isaiah%207%3A14&f=false
so it is quite clear that "parthenos" predates the split of the Jews from Christianity.
But back to Theodotion. He produced a translation which the Church Fathers preferred to the LXX text of Daniel. The problem is that Theodotion's translation includes what is now called Susanna, the Song of the Three Youths, and Bel and the Dragon, which the LXX includes but the Masorah rejects. Again, Theodotion was a Jew translating for Jews, and so he would have no reason to alter his text towards the Church's LXX. This is parralleled by Sirach, which the Masorah rejected but the Talmud comments on. Then there is the Jewish feast of Hanukkah, whose only Scriptural warrant comes from Maccabbees, a book the LXX includes but the Masorah rejected (of importance, as the NT shows Christ celebrated Hanukkah).
and then there is the Masoretic Text's testimony to the LXX itself: the MT divides Psalm 9 into Ps. 9 and Ps. 10. However, the Pslam is a poem where the lines end in the letters of the alphabet in order: the MT divides the alphabet, whereas LXX Ps. 9-with no reference to the acrostic-preserves the alphabet whole.