Notes from the Asbury Bible Commentary (available online here) on Romans 9:
“The Israelites have not yet received the salvation God promised Abraham and his descendants. It seems that God’s promise has failed. But this is not the case. Not all of Abraham’s descendants are the heirs of promise. His heirs do receive salvation (11:1-10). How do we, then, determine who are his heirs? God is sovereign. He decides what kind of people are Abraham’s heirs. Paul appeals to the OT to demonstrate this. This section has been misinterpreted to mean that God arbitrarily determines the destiny of people, regardless of their action and behavior (Murray, 2:20, 24). Paul’s thought development and the context of the OT quotations and allusions demonstrate the opposite.
The sovereignty of God, emphasized in this section, can be understood in two different ways. (1) God arbitrarily decides who are and who are not Abraham’s heirs. The unsaved Jews are not saved because God arbitrarily decides that they are not Abraham’s heirs. In this case, they are not responsible since they cannot do anything about it. (2) God is free to lay down the condition of heirship and thus determine what kind of people will be Abraham’s heirs (Wesley, Notes, 388). The Jews are not saved because they do not comply with God’s condition. Therefore they are responsible for their condition and are guilty.
If the first interpretation were true, the quotations from Hosea and Isaiah in 9:25-29 are meaningless. Why would God first arbitrarily reject them and later change his mind to accept them? The entire section following 9:30 indicates and 11:20-23 explicitly states that these Jews are unsaved precisely because of their unbelief, not because of God’s arbitrary decision to count them out. If they do not persist in their unbelief, they also will be saved. This surely contradicts the first and supports the second interpretation. The statement in 10:21 that God has held out his hands to a disobedient people (Israel) has the same effect. So does Paul’s anguish for the Israelites (9:1-5). All these lead to this conclusion: God’s sovereignty consists in his freedom to lay down the condition of salvation, not in his arbitrary consignment of some to salvation, others to damnation.
In the OT not all the descendants of Isaac are Abraham’s heirs. Even before Jacob and Esau were born, God had already laid down the condition of heirship. God did not wait until after they were born and then pick a condition favorable to jacob (vv. 10-13). God proclaimed before Moses, “I will have mercy on whom I have mercy” (cf. Ex 33:19). The meaning, again, is that I decide what kind of people I will show mercy to (cf. Ex 32:33). God showed mercy to Moses because, while the Israelites worshiped idols, Moses did not (Ex 32:1-33:23). God shows mercy to those who are faithful (vv. 14-15) and hardens the heart of those who oppose him. In Ex 5:1-12:51 Pharaoh first hardened his own heart. Only after that did God harden his heart (vv. 16-18).
The potter has the right to make out of the same lump of clay, some pottery for noble purposes and some for common use (v. 21). This is an allusion to Jer 18:5-12. The true meaning is clearly spelled out in Jer 18:6-10:
“Like clay in the hand of the potter, so are you in my hand, O house of Israel. If at any time I announce that a nation or a kingdom is to be uprooted, torn down and destroyed, and if that nation I warned repents of its evil, then I will relent and not inflict on it the disaster I had planned. And if at another time I announce that a nation or kingdom is to be built up and planted, and if it does evil in my sight and does not obey me, then I will reconsider the good I had intended for it.”
The sovereignty of the potter over the clay means that the Lord is completely free to lay down the conditions under which he will bless or punish. It is not his arbitrary decision to consign some to salvation and others to damnation (vv. 19-21).
This truth is illustrated in vv. 22-29. Originally Gentiles were not God’s people, but God will accept them as his own because of their faith. The Israelites were God’s people, but because of their unbelief, they will be judged.” (Emphasis in original)