I have a different take on this JGig.
First of all, a translation is not a quote. A quote must be exact to be a quote. If you take a Hebrew sentence and translate it, the translation is not a quote. Now it is possible for a Greek document (like the NT) to quote another Greek document. But I don't think there is any way to establish that the NT quotes the LXX. The reason is that we don't have any LXX manuscript that predates the NT, except for fragments, so far as I know. What we have and what is called the LXX is really not the LXX, but the Greek OT, as attached to great codexes of the NT, no earlier than 4th century AD.
So what would you have done had you been a Christian living in AD 300 and wanted an accurate Old Testament in Greek? If it had been me, I would have preferred the NT's presentation of the Old Testament and incorporated NT readings as better than the uninspired LXX. Thus, I think that our so-called LXX manuscripts have been altered to agree with the NT at times; so you can't know that the NT is copying the LXX at any point.
What we have in the NT is the Holy Spirit giving us the gist of OT passages in Greek, not quotations. Also, we probably do not have verbatim sayings of the Lord Jesus (probably uttered in Aramaic), but the gist of what He said in Greek as accurately expressed by the Holy Spirit. So if the Lord Jesus refers to the OT (It is written), we don't have exactly what He said -- He may well have quoted it in Hebrew instead of Aramaic. I suppose He could have given the gist of the OT in Aramaic, a cognate language. I highly doubt that the Lord Jesus quoted from the LXX in Greek.
Thus, I don't accept the theory that the NT quotes the LXX.
First of all, a translation is not a quote. A quote must be exact to be a quote. If you take a Hebrew sentence and translate it, the translation is not a quote. Now it is possible for a Greek document (like the NT) to quote another Greek document. But I don't think there is any way to establish that the NT quotes the LXX. The reason is that we don't have any LXX manuscript that predates the NT, except for fragments, so far as I know. What we have and what is called the LXX is really not the LXX, but the Greek OT, as attached to great codexes of the NT, no earlier than 4th century AD.
So what would you have done had you been a Christian living in AD 300 and wanted an accurate Old Testament in Greek? If it had been me, I would have preferred the NT's presentation of the Old Testament and incorporated NT readings as better than the uninspired LXX. Thus, I think that our so-called LXX manuscripts have been altered to agree with the NT at times; so you can't know that the NT is copying the LXX at any point.
What we have in the NT is the Holy Spirit giving us the gist of OT passages in Greek, not quotations. Also, we probably do not have verbatim sayings of the Lord Jesus (probably uttered in Aramaic), but the gist of what He said in Greek as accurately expressed by the Holy Spirit. So if the Lord Jesus refers to the OT (It is written), we don't have exactly what He said -- He may well have quoted it in Hebrew instead of Aramaic. I suppose He could have given the gist of the OT in Aramaic, a cognate language. I highly doubt that the Lord Jesus quoted from the LXX in Greek.
Thus, I don't accept the theory that the NT quotes the LXX.
-JGIG