What follows is an analysis of Paul’s Old Testament quotations in Romans 9:7-13:

Item #1 is identical in the Septuagint and the parallel Greek text except that the accent mark is missing from before Ισαακ (Isaac) in the Septuagint [Addendum 3/7/2025: the Elpenor Septuagint has the accent marks: ᾿Ισαὰκ.].  The Greek word κληθήσεταί, translated counted in the NET above, is a form of καλέω, like ἐκάλεσεν:  And those he predestined, he also called (ἐκάλεσεν); and those he called (ἐκάλεσεν), he also justified; and those he justified, he also glorified.³  But in this particular form it is called as in a designation:  Jesus would be called (ἐκάλεσα, another form of καλέω) a Nazarene.⁴  So anyone who breaks one of the least of these commands and teaches others to do so will be called (κληθήσεταί) least in the kingdom of heaven, but whoever obeys them and teaches others to do so will be called (κληθήσεταί) great in the kingdom of heaven.⁵

Item #2 began ἥξω (I will come) πρὸς σὲ (to you) in the Septuagint followed by the prepositional phrase κατὰ τὸν καιρὸν τοῦτον.  In Revelation 3:3 (NET) ἥξω was translated I will come both times it occurred:  If you do not wake up, I will come (ἥξω) like a thief, and you will never know at what hour I will come⁶ (ἥξω) against you.⁷  Paul left off πρὸς σὲ (to you) and (after the prepositional phrase κατὰ τὸν καιρὸν τοῦτον) chose ἐλεύσομαι, which was also translated I will come in Romans 15:29 and 1 Corinthians 4:19 (NET).  Paul also left off εἰς ὥρας (next year or in due time).  The differences in the final phrases are detailed in Note #5 below.  The repetition of that phrase in Genesis 18:14 was identical to Paul’s construction.  I consider this a paraphrase more than a quotation.

Item #3 is identical in the Septuagint and the New Testament.  While it is certainly not wrong to translate μείζων older and ἐλάσσονι younger in this context, it hides a nuance that they might have been translated greater and lesser respectively.  Who is the greatest (μείζων) in the kingdom of heaven?⁸  He called a child, had him stand among them [Table], and said, “I tell you the truth, unless you turn around and become like little children, you will never enter the kingdom of heaven!  Whoever then humbles himself like this little child is the greatest (μείζων) in the kingdom of heaven [Table].⁹

Item #4 only differs in the word order of the first phrase (and some accent marks on Ιακωβ [Jacob] and Ησαυ [Esau]): ἠγάπησα τὸν Ιακωβ (I loved Jacob) in the Septuagint; τὸν Ἰακὼβ ἠγάπησα (Jacob I loved) in the New Testament.

What follows is an analysis of Paul’s Old Testament quotations in Romans 9:15-20:

Item #5 is the same in the Septuagint and the New Testament.

In Item #6 the second clause καὶ ὅπως διαγγελῇ τὸ ὄνομά μου ἐν πάσῃ τῇ γῇ (and that my name may be proclaimed in all the earth) is identical in both the Septuagint and the New Testament except that the accent mark is missing from α at the end of ὄνομα (name) in the parallel Greek text.  According to Bill Braun¹⁶ “The main difference in this citation is the use of a different verb in this first clause.  The NT uses the Greek verb ἐξήγειρά (ἐξεγείρω– 1s-AAI- Mng.- to raise up; bring into being; elevate (BDAG, 346); Trans.- elevated).  The LXX uses the verb διετηρήθης (διατηρέω -2s-API- Mng.- to preserve (GELS); Trans.- you have been preserved).  Certainly these verbs are different….In this case the LXX does follow the sense of the MT better since the Hebrew verb הֶעֱמַדְתִּיךָ (עָמַד -H-14; x2ms; Mng.- to cause to stand firm; maintain (BDB, 764); Trans.- caused to stand firm (or remain)) is very close in meaning.”¹⁷

As I contemplated why he deliberately changed the word, it came to me that Paul wasn’t grappling with the relatively minor issue of why God kept or preserved a harsh ruler over his people longer than they thought He should.  Paul was entertaining the alarming possibility that his contemporaries, men he studied the Torah with, his brothers, fellow Israelites, might have been raised up or brought into being by God only to be condemned for eternity.  His anguish is palpable:  I have great sorrow and unceasing anguish in my heart.  For I could wish that I myself were accursed – cut off from Christ – for the sake of my people, my fellow countrymen [Table], who are Israelites.¹⁸

The minor differences are as follows:  Paul began with the phrase εἰς αὐτὸ τοῦτο (for this very purpose).  The Septuagint began καὶ ἕνεκεν τούτου (NETS: and for this reason).  Paul used a different conjunction ὅπως (in such manner as) than ἵνα (in that place) in the Septuagint.  Paul chose δύναμίν over ἰσχύν (strength).  There are enough differences in the first clause that I find it difficult to think of as a quotation.  It is more like an amplification of Paul’s point:  So then, God has mercy on whom he chooses to have mercy, and he hardens whom he chooses to harden.¹⁹

It stands as an allusion to, So the Lord said to Moses, “See, I have made you like God to Pharaoh, and your brother Aaron will be your prophet.  You are to speak everything I command you, and your brother Aaron is to tell Pharaoh that he must release the Israelites from his land.  But I will harden Pharaoh’s heart, and although I will multiply my signs and my wonders in the land of Egypt, Pharaoh will not listen to you.”²⁰  This mirrored Paul’s experience too often to pass without comment.

Item #7 doesn’t seem like a quote at all to me, beyond the introductory phrase μὴ ἐρεῖ τὸ πλάσμα τῷ πλάσαντι (does what is molded say to the molder).  Instead it points to Paul’s reasoning process.  Here are the relevant texts (Isaiah 29:16; 45:9 NET)

Your thinking is perverse!  Should the potter be regarded as clay?  Should the thing made say about its maker, “He didn’t make me”?  Or should the pottery say about the potter, “He doesn’t understand”? [Table]

One who argues with his creator is in grave danger, one who is like a mere shard among the other shards on the ground!  The clay should not say to the potter, “What in the world are you doing?  Your work lacks skill!” [Table]

If it is perverse to regard the potter as clay, and for the thing made to say about its maker, “He didn’t make me,” or “He doesn’t understand,” then it is likewise perverse for what is molded to say to the molder, “Why have you made me like this?” (specifically, why have you hardened me like this?).  It puts one in grave danger, like the clay saying to the potter, “What in the world are you doing?  Your work lacks skill!”

And again, one who hears and fears this is hearing the word of God.  God is calling.  Hear also the words that brought comfort and hope to Paul’s anguish:  “I will call those who were not my people, ‘My people,’ and I will call her who was unloved, ‘My beloved.’”  “And in the very place where it was said to them, ‘You are not my people,’ there they will be called ‘sons of the living God.’”²¹

Addendum: March 13, 2025
Tables comparing Exodus 7:1; 7:2; 7:3 and 7:4 in the Tanakh, KJV and NET, and tables comparing the Greek of Exodus 7:1; 7:2; 7:3 and 7:4 in the Septuagint (BLB and Elpenor) follow.