(Rom 10:18) But I ask: Did they not hear? Of course they did: “Their voice has gone out into all the earth, their words to the ends of the world.”
Paul quotes Ps 19:4, which speaks of God’s self-revelation through the Creation (vv. 1 – 6) and then his self-revelation through the word (vv. 7 -14). God has sufficiently revealed his will to Israel that they should believe!
(Rom 10:19) Again I ask: Did Israel not understand? First, Moses says, “I will make you envious by those who are not a nation; I will make you angry by a nation that has no understanding.”
Paul quotes —
(Deu 32:20-22) “I will hide my face from them,” he said, “and see what their end will be; for they are a perverse generation, children who are unfaithful. 21 They made me jealous by what is no god and angered me with their worthless idols. I will make them envious by those who are not a people; I will make them angry by a nation that has no understanding. 22 For a fire has been kindled by my wrath, one that burns to the realm of death below. It will devour the earth and its harvests and set afire the foundations of the mountains.”
Here, near the end of Deuteronomy, God speaks of his wrath against Israel when she is unfaithful. And he says I will provoke Israel to jealousy through other peoples.
(Rom 10:20-21) And Isaiah boldly says, “I was found by those who did not seek me; I revealed myself to those who did not ask for me.” 21 But concerning Israel he says, “All day long I have held out my hands to a disobedient and obstinate people.”
Paul quotes Isa 65, where God speaks of his frustration with the idolatry of Israel and his plan to deal with it —
(Isa 65:1-7) “I revealed myself to those who did not ask for me; I was found by those who did not seek me. To a nation that did not call on my name, I said, ‘Here am I, here am I.’ 2 All day long I have held out my hands to an obstinate people, who walk in ways not good, pursuing their own imaginations– 3 a people who continually provoke me to my very face, offering sacrifices in gardens and burning incense on altars of brick; 4 who sit among the graves and spend their nights keeping secret vigil; who eat the flesh of pigs, and whose pots hold broth of unclean meat; 5 who say, ‘Keep away; don’t come near me, for I am too sacred for you!’ Such people are smoke in my nostrils, a fire that keeps burning all day.
6 “See, it stands written before me: I will not keep silent but will pay back in full; I will pay it back into their laps– 7 both your sins and the sins of your fathers,” says the LORD. “Because they burned sacrifices on the mountains and defied me on the hills, I will measure into their laps the full payment for their former deeds.”
God again speaks of rejecting Israel and accepting others, in response to Israel’s disobedience and idolatry.
Paul’s point in chapter 10 is that God had said throughout the Old Testament — from both the Law and the Prophets — that if Israel rejects him, God will reject Israel, other than only a remnant. God will keep his covenant, by keeping a remnant to be saved, but the nation as a whole will be rejected.
Therefore, the supposedly surprising result that most of Israel will be lost is no surprise at all. It is, in fact, precisely what God said would happen.
Notice that none of these passages speak in terms of God hardening hearts or predestining the outcome. Rather, the passages speak in terms of the penalties for being faithless.
Paul’s argument is not yet over, of course. He completes it in chapter 11.