In the earlier part the history of the text is closely bound up with the history of the Canon—the history, that is, of how and when the several books came into existence, and how and when they were accepted by the Hebrews as the authoritative sacred books of their faith.
The Massoretic text, as we have seen, is substantially the same as that which was used by the writers of the Talmud, and the way in which the writers of the Talmud speak of it shows that it had been in existence for some time previously.
The text is correctly written, and furnishes a strong proof of the truth of the assertion that all extant Hebrew MSS.
It's original text, much of the New Testament, but with considerable gaps (and completely missing II Thessalonians and II John), was erased during the twelfth century and then used for writing the text of the sermons of St. Ephraemi.
They considered the Syrian text, represented mainly by Codex Alexandrinus (A 02) in the gospels and the bulk of the later minuscules, to be a conflation of earlier textual families and are useful mainly for "recitation" and not for "diligent study"; in other words, of very little textual value.
The reason that justifies one in discarding the Koine type of text is that it is based on the recension prepared near the close of the third century by Lucian of Antioch, or some of his close associates, who deliberately combined elements from earlier types of text.