It is commonly referred to as LXX meaning 70 and based on supposedly having 72 translators and rounding to 70 . The reason it is so important is it shows us several things about how God views translations. (We can ascertain how God feels about it due to Jesus quoting from it.)We know the apostles used it because their NT quotes match it. This tells us several things.
- It is okay to have a translation in the common language of the day.
- It is okay for the translation to be regularly revised.
- Minor differences are to be expected and are okay if they do not change the meaning.
The Septuagint is different from the Hebrew text in several places. Most of these do very little to change the meaning. These differences can be assigned to many reasons such as the act of translating itself, harmonization of verses, or a problem with the manuscript. Any time you take something and put it in another language there will be differences. Some languages are more colorful, the sentence structures are different, grammatical rules are different. This can cause changes. Jesus accepting the use of the Septuagint shows that this is acceptable.
The best known manuscripts today are; Codex Vaticanus dating to the fourth century and found in the Vatican library, Codex Sinaiticus dating to the fourth century found in the St Catherine’s monastery at the base of Mt Sinai, and Codex Alexandrinus dating to the fifth century.
Just as an example of what the Greek and Hebrew would look like I’ve included Genesis 1:1 from the each.
Hebrew (read right to left)
בראשׁית ברא אלהים את השׁמים ואת הארץ׃
Ἐν ἀρχῇ ἐποίησεν ὁ θεὸς τὸν οὐρανὸν καὶ τὴν γῆν.