Christian readers are sometimes puzzled when they read a quotation from the Old Testament in the New Testament, and then, in looking up the quoted Old Testament text in their Bible, they discover that it is somewhat different from the cited quotation in the New Testament. Often, this difference is based on the fact that the Old Testament has been trans­lated from Hebrew Scripture Master Texts which are primarily based the manuscripts of the Hebrew Bible from the Masoretic text of the 6th to 10th centuries C.E., whereas the New Testament is citing the same passage as it appears in the early Greek translation of the Old Tes­tament, known as the Greek Septuagint Version (LXX).

The fact is that the writers of the New Testament generally quoted or paraphrased their quotes of the Old Testament from the LXX.

The Greek Septuagint was used by Hellenistic Jews, and by the early church. Greek was the international language of communication. Most scholars believe that the Greek translation of the Pentateuch (Genesis through Deuteronomy) was produced by Jewish scholars in the mid-to-late-third century B.C.E. in Alexandria, Egypt. The rest of the Old Testa­ment was completed during the following century or so. Apocryphal writings were added after this. This means the Septuagint was virtually complete about 150-200 years before the time of Christ. Some parts of the Septuagint reflect a more literal approach to translation, while others provide a freer rendition. Some portions are also more skillfully translated than others. Sometimes the Septua­gint translators translated from a Hebrew text that differed slightly from the later, now standard, Masoretic text of the Hebrew Bible.

The Greek Septuagint Version (LXX) has been preserved in many Greek manuscripts, most them fragmentary, but some of the fairly complete. The most famous of these are the Vatican Manuscript 1209 (almost 100% complete), and the Sinaitic Manuscript (only partial), both of the 4th century, and the Alexandrine Manuscript (mostly complete, except for parts of Genesis, 1 Samuel and Psalms) of the 5th century.

The Septuagint (LXX) is the version of the Old Testament with which early Greek-speaking Christians would have been familiar. It had been used by most Jews in the Roman Empire. Naturally, then, most of the Old Testament quota­tions found in the New Testament reflect its influence. There are about 90 direct quotations in the New Testament from the  LXX, and about 80 paraphrases or allusions to it. In the vast majority of instances the Septuagint agrees with the Masoretic text—if not word-for-word, at least in basic thrust. In a few cases the Septuagint may even reflect the original Hebrew text better than the Masoretic text does. The Masoretic text may, for instance, contain a copyist’s error, so that it does not at a given point accurately reflect the original Hebrew text. Sometimes, in such cases, the Greek reading in the Septuagint allows scholars to reconstruct what was in the original Hebrew manuscript (most modern translations of the Old Testament are based on the Masoretic text, with occa­sional emendations drawn from the Septuagint and other early Versions). This fact gives evidence to support what the scriptures say about God preserving his word:

“All people are like grass, and all their glory is like flowers of the field; the grass withers and the flowers fall, but the word of the Lord endures forever”—1 Peter 1:24,25 NIV

When a New Testament writer followed the Septuagint, the validity of his argument is generally not dependent upon peculiarities of the Septuagint rendering as over against the Masoretic text. In other words, the New Testament writers did not cite the Septuagint because it said what they wanted it to say, while the Hebrew text did not, nor were they implying that the Septuagint is superior to the Hebrew. Rather, they cited the Septuagint because their readers were familiar with it—as well as, in general, with the Greek language. It was impor­tant to bear in mind that the Septuagint was prepared, not by Christians, but by Jewish scholars before the coming of Christ. Work on the Septuagint started around 280 BCE, and was completed by about 150 BCE. Therefore, when the writers of the New Testament quoted the Septuagint, they could not be accused of using a translation that was prepared with their vested interests in mind.

When Hebrews 11:21 states that “by faith Jacob, when he was dying, blessed each of Joseph’s sons, and worshiped as he leaned on the top of his staff,” the last clause agrees perfectly with the Septuagint rendering of Genesis 47:31. The Masoretic text, on the other hand, states that Jacob worshiped “on the top of his bed.” The author of Hebrews quoted the version of Scripture known to his readers to make the point that Jacob was a man of faith, and that, even as he lay dying, his faith led him to bless his sons (trust­ing that God would fulfill the blessing). Whether Jacob was lean­ing on his staff or lying on his bed is not essential to the ar­gument in Hebrews. Citing the text in the form known to the author’s contemporary readership would not have diminished its validity, but rather would have made it easier for the audience to recognize a Scriptural citation.

One notable example of where the Septuagint has words that the traditionally used Hebrew manuscripts does not is Deuteronomy 32:43. Let’s notice the difference. First let’s look at how the Hebrew Text is translated:

“Rejoice, you nations, with his people, for he will avenge the blood of his servants; he will take vengeance on his enemies and make atonement for his land and people”—Deuteronomy 32:43 NIV 

Now notice the additional words as we look at the Septuagint (LXX):

“Be glad, O skies, with him, and let all the divine sons do obeisance to him. Be glad, O nations, with his people, and let all the angels of God prevail for him. For he will avenge the blood of his sons and take revenge and repay the enemies with a sentence, and he will repay those who hate, and the Lord shall cleanse the land of his people”—Deuteronomy 32:43 NETS

Notice the words, “Let all the divine sons of God do obeisance to him.” The Dead Sea Scrolls (DSS) reading is similar, which indicates the Hebrew Text at the time must have had at least some of the additional words:

“Rejoice, O heavens, together with him; and bow down to him all you gods, for he will avenge the blood of his sons, and will render vengeance to his enemies, and will recompense those who hate him, and will atone for the land of his people”—Deuteronomy 32:43 The Dead Sea Scrolls Bible

Notice the words, “Bow down to him all you gods.” Now, notice how Hebrews 1:6 quotes part of Deuteronomy 32:43 from the Septuagint:

“Again, when he brings his First-born into the world, he says: Let all the angels of God pay him homage”—Hebrews 1:6 NJB

Most translations of Hebrews 1:6 translate the Greek “proskyneo” as “worship”, but as we can see from the LXX and the DSS, “proskyneo” is actually better translated as: “do obeisance”, “bow down to him”,  or “pay him homage”. In any case, the main point is that when the LXX is quoted, its quoted words are part of inspired scripture in the New Testament (2 Timothy 3:16).

One Source: NIV Archaeological Study Bible