After saying that most of Israel was blinded, Paul knows what a reader might conclude: God is finished with them. So he asks it out loud. Barnes calls the question "an objection, which the apostle proceeds to answer," and Gill says Paul takes it "from the mouth of an adversary." The question presses one point: was Israel's stumbling meant to end in a final fall, with no recovery?

Paul answers with his strongest denial: "God forbid" (Romans 11:11). Barnes reads it as "By no means," the same denial Paul gave in Romans 11:1. Then Paul shows what God was actually doing: "through their fall salvation is come unto the Gentiles, for to provoke them to jealousy" (Romans 11:11). He carries the thought forward with two more questions about Israel's future (Romans 11:12, 15).

"Stumbled" translates ptaiō, to stumble, and "fall" translates piptō, to fall. "God forbid" is the Greek mē genoito, literally "may it not be," a strong refusal Paul uses throughout Romans. "Provoke to jealousy" is parazēloō, to make jealous. Barnes ties the phrase to Moses' prediction in Deuteronomy 32:21, "I will move them to jealousy with those which are not a people," which Paul had already quoted in Romans 10:19. Barnes says the "fall" refers to "all their conduct and doom at the coming of the Messiah, and in the breaking up of their establishment as a nation."

This question shows how God works through what looks like loss. Israel's stumbling did not end God's plan. He used it to open salvation to the nations, and He aimed even that at Israel's good. Gill takes the jealousy in a good sense: as Israel sees the Gentiles blessed through the Messiah, they would be stirred to seek Him too.

So God's purpose runs in a circle of mercy. Israel's fall brings salvation to the Gentiles, and the Gentiles' blessing is meant to draw Israel back. Paul sums it up later: "God hath concluded them all in unbelief, that he might have mercy upon all" (Romans 11:32).