God's unconditional commitment to Israel is brought out in verses 35-37. Speaking of the sun, the moon, and the stars, God says, "If those ordinances depart from before me, saith the Lord, then the seed of Israel also shall cease from being a nation before me for ever." Then He says, "If heaven above can be measured, and the foundations of the earth searched out beneath, I will also cast off all the seed of Israel for all that they have done, saith the Lord."
Some of God's promises to Israel were conditional upon their response to Him. But this passage makes it clear that His selection of them as His people is permanent, in spite of "all that they have done." Their behavior cannot change His choice of them as His covenant people.
Popular "replacement theology" teaches that the Christian church replaces the Jewish nation as God's covenant people. But the Bible does not teach that. The Bible makes it clear that in order for Gentiles to experience the blessings of the new covenant they must be grafted into Israel. Not the modern nation of Israel, but the kingdom of David, for Jesus will sit on David's throne.
For a more complete study of this subject see "'Thy People' and the Remnant of Israel" posted on May 21, 2019.