Hebrew? You mean the Pharisaical Bible that was 'redacted' several times since the time of Christ to 'purge' Chriastian bias out of it through Talmud and Mishna?
The 'Hebrew' you read is book that had accent vowells added (and such changes change words not just the accent). And the oldest copy goes to the 9th century AD! That is CE in modern usage. Over eight hundred years after Christ.
The LXX has been a "Hebrew" Bible because it was intended for the Alexandrian Hebrews, translated and bound and all that neatly two hundred years BEFORE Christ, that is BC (or BCE modern).
The Dead Sea Scrolls are "Hebrew" Bible too. And the LXX is what the Apostles quoted as OT Scripture.
Oh, please. -t w-ht p--nt d-d th- Gr--ks p-t th- v-w-ls b-ck -n th- scr-pt-r-s?
Faith comes from God's word, not from tradition.