Why does Paul stop talking about Gentiles and turn to Israel in Romans 9?
Paul turns to Israel in Romans 9 because this section is parenthetical: he leaves off his instructions and doctrines for Gentiles to deal with the nation of Israel for three chapters—past, present, and future. His great heaviness and continual sorrow reveal his love for the Jew.
Les explains that Romans 9 begins a parenthetical section in the book of Romans. After Paul completes his instructions and doctrines for Gentiles, he leaves off that subject and deals with the nation of Israel for three chapters: past, present, and future. Paul’s sorrow is personal: he says he has great heaviness and continual sorrow in his heart and could wish himself accursed from Christ because of his love for the Jew. Les compares this to Moses, who asked God to spare Israel and even offered to have his name blotted out of the book of life if it would help.