Dear Fran
Ok a lot here. But basically, the apostles and Jesus used bothe the Hebrew text ( which came to be the Masoretic text and the LXX..
St Paul quotes 80% of his biblical quotes from the LXX.
In addition, the "other" books not included in the Hebrew canon are cited as Scripture in the NT both be Jesus and St Paul
Here are some examples of text quoted from the LXX version.
Mat. 3:3. The Hebrew of Isa. 40:3 may be rendered, “The voice of one crying, In the wilderness prepare the way for the Lord.” The crier himself is not necessarily in the wilderness: the path is to be prepared in the wilderness. Matthew follows the Septuagint in construing “in the wilderness” with “one crying,” and so renders “The voice of one crying in the wilderness, Prepare the way of the Lord.” Here the cry comes from one who is himself in the wilderness, that is, from John the Baptist, who habitually preached in the wilderness of Judea.
Mat. 12:21. The Hebrew of Isa. 42:4 reads, “and the isles shall have hope in his law.” Matthew follows the Septuagint interpretation of this, “and the Gentiles shall have hope in his name.”
Mat. 13: 14-15. The Hebrew of Isa. 6:9-10 reads, “Hear ye indeed, but understand not; and see ye indeed, but perceive not. Make the heart of this people fat, and make their ears heavy, and shut their eyes; lest they see...” Matthew follows the Septuagint in changing the first sentence from two commands to the people into a prophetic description of the people, “Ye shall surely hear, but shall not understand; ye shall surely see, but shall not perceive.” He also follows the Septuagint in changing the second sentence from two commands to the prophet into a description of the present condition of the people: “This people’s heart has become gross, and their ears are dull of hearing, and their eyes they have closed; lest they see...”
Mat. 15:8-9. The Hebrew of Isa. 29:13 reads (somewhat obscurely), “their worship of me is but a commandment of men which hath been taught them.” The phrase, “but in vain do they worship me,” in which Matthew follows the Septuagint, was created by the translator of the Septuagint by separating “their worship of me” from the words that follow and supplying the thought “is in vain” to complete the sense, and then construing the rest of the sentence adverbially, “teaching the precepts and doctrines of men.” The sense of the passage is not materially changed in this.
Mat. 21:16. The Hebrew of Psa. 8:2 reads, “out of the mouth of babes and sucklings thou hast established strength.” Matthew follows the Septuagint with “thou hast prepared praise.”
Mark 1:2. See remarks on Mat. 3:3 above.
Mark 4:12. See remarks on Mat. 13:14-15 above. Mark departs from both the Hebrew and Septuagint with the interpretation, “and it should be forgiven them,” instead of “and I should heal them” (Septuagint) or “and be healed” (Hebrew).
Mark 7:6-7. See remarks on Mat. 15:8-9 above.
Luke 3:4. See remarks on Mat. 3:3 above.
Luke 3:5-6. The Hebrew of Isa. 40:4-5 reads “every valley shall be exalted...all flesh shall see it [i.e., the glory of the Lord] together.” Luke follows the Septuagint with “every valley shall be filled...all flesh shall see the salvation of God.”
Luke 4:18. The Hebrew of Isa. 61:2 reads merely “the opening to them that are bound,” which may mean the opening of prisons. Luke follows the Septuagint interpretation, “the recovering of sight to the blind,” in which the “opening” is of blind eyes, but adds “to set at liberty the afflicted” as an alternative interpretation of the Hebrew. The phrase “to bind up the broken-hearted” (Septuagint “to heal the broken-hearted”) has been left out of the quotation.
Luke 8:10. The allusion to Isa. 6:9 conforms to the Septuagint. See remarks on Mat. 13:14-15 above.
John 1:23. See remarks on Mat. 3:3 above. John’s quotation is somewhat looser.
John 12:34. There is a verbal correspondence here to the Septuagint of Psa. 89:36, “his [David’s] seed shall abide forever.”
John 12:38. “Lord” at the beginning of the quotation is not in the Hebrew, but in the Septuagint.
John 12:40. See remarks on Mat. 13:14-15 and Mark 4:12 above. John is quoting the Septuagint loosely, with reference to the Hebrew.
Acts 2:19-20. The Hebrew of Joel 2:30-31 has “pillars of smoke” and “terrible day.” Luke follows the Septuagint with “vapour of smoke” and “glorious day.”
Acts 2:26. The Hebrew of Psa. 16:9 has “my glory rejoiceth.” Luke follows the Septuagint with “my tongue rejoiced.”
Acts 2:28. The Hebrew of Psa. 16:11 has “in thy presence is fulness of joy; in thy right hand there are pleasures for evermore.” Luke follows the Septuagint in paraphrasing the first clause “Thou shalt make me full of gladness with thy countenance,” and in dropping the last clause.
Acts 4:26. The Hebrew of Psa 2:2. reads, “the rulers take counsel together.” Luke follows the Septuagint, “the rulers were gathered together.”
Acts 7:14. The Hebrew of Gen. 46:27 and Exod. 1:5 has “seventy.” Luke follows the Septuagint with “seventy-five.”
Acts 7:43. The Hebrew of Amos 5:26 is difficult. It seems to say, “ye took up the tabernacle of Moloch and Chiun your images , the star of your god, which ye made.” Luke follows the Septuagint interpretation with “ye took up the tabernacle of Moloch and the star of the god Rephan, the figures which ye made.”
Acts 8:33. The Hebrew of Isa. 53:8 reads “he was taken away by distress and judgment.” Luke follows the Septuagint with “in his humiliation his judgment was taken away.”
Acts 13:34. The Hebrew of Isa. 55:3 has “the sure mercies of David.” Luke follows the Septuagint with “the holy and sure things of David.”
Acts 13:41. The Hebrew of Habakkuk 1:5 reads, “Behold, ye among the nations, and look, and wonder exceedingly.” The Septuagint has “Behold, ye despisers, and look, and wonder exceedingly, and perish,” which Luke largely follows.
Acts 15:17. The Hebrew of Amos 9:12 reads “that they may possess the remnant of Edom, and all the nations upon whom my name is called.” The Septuagint has “that the remnant of men and all the nations upon whom my name is called may seek after [me],” which Luke largely follows.
Is the Catholic Old Testament Accurate