**The Septuagint was used exclusively by Greek-speaking Jews who lived in the Mediterranean area. It is the translation of the Hebrew Bible into the Greek language. The name “Septuagint” comes from the Latin word for seventy. The tradition is that 70 (or 72) Jewish scholars were the translators behind the Septuagint. The Septuagint was translated in the third and second centuries B.C. in Alexandria, Egypt. As Israel was under the authority of Greece for several centuries, the Greek language became more and more common. By the 2nd and 1st centuries B.C., most people in Israel spoke Greek as their primary language. That is why the effort was made to translate the Hebrew Bible into Greek – so that those who did not understand Hebrew could have the Scriptures in a language they could understand. The Septuagint represents the first major effort at translating a significant religious text from one language into another.
By the late 1st century B.C., and especially the 1st century A.D. – the Septuagint had “replaced” the Hebrew Bible as the Scriptures most people used. Since most people spoke and read Greek as their primary language, and the Greek authorities strongly encouraged the use of Greek, the Septuagint became much more common than the Hebrew Old Testament. The fact that the Apostles and New Testament authors felt comfortable, under the direction of the Holy Spirit, in using the Septuagint should give us assurance that a translation of the original languages of the Bible is still the authoritative Word of God.
The Jews did not define a canon of their Scriptures until 90 AD. The Septuagint contained more books than are currently found in Protestant version of the Old Testament today. They include 1, 2, & 3 Maccabees, Tobit, Judith, Sirach, Baruch, Wisdom, Esdras, and longer versions of Daniel and Esther. Some scholars believed these to be unique to the Alexandrian Greek-Jewish community, but fragments of all of them have been found in Hebrew and/or Aramaic among the Dead Sea Scrolls, so they had wide, multi-lingual circulation.
Most Protestant-version Bibles use the Septuagint quotes in the New Testament, but if you cross-reference back to the Old Testament, they use the Hebrew rendering.Go figure.
Your scholarly protestant friend is smart, but not smart enough.**