The apostle's concern for the Jews. God's election is free and not confined to their nation.
9:1. I speak the truth in Christ: I lie not, my conscience bearing me witness in the Holy Ghost:
9:2. That I have great sadness and continual sorrow in my heart.
9:3. For I wished myself to be an anathema from Christ, for my brethren: who are my kinsmen according to the flesh:
Anathema… A curse. The apostle's concern and love for his countrymen the Jews was so great, that he was willing to suffer even an anathema, or curse, for their sake; or any evil that could come upon him, without his offending God.
9:4. Who are Israelites: to whom belongeth the adoption as of children and the glory and the testament and the giving of the law and the service of God and the promises:
9:5. Whose are the fathers and of whom is Christ, according to the flesh, who is over all things, God blessed for ever. Amen.
9:6. Not as though the word of God hath miscarried. For all are not Israelites that are of Israel.
All are not Israelites, etc… Not all, who are the carnal seed of Israel, are true Israelites in God's account: who, as by his free grace, he heretofore preferred Isaac before Ismael, and Jacob before Esau, so he could, and did by the like free grace, election and mercy, raise up spiritual children by faith to Abraham and Israel, from among the Gentiles, and prefer them before the carnal Jews.
9:7. Neither are all they that are the seed of Abraham, children: but in Isaac shall thy seed be called.