Rom. 3:1 What advantage then hath the Jew? or what profit is there of circumcision? 2 Much every way: chiefly, because that unto them were committed the oracles of God.
IMO, Paul resumes answering the question of Rom 3:1 here:
Rom 9
4 who are Israelites; whose is the adoption, and the glory, and the covenants, and the giving of the law, and the service of God, and the promises;
5 whose are the fathers, and of whom is Christ as concerning the flesh, who is over all, God blessed for ever. Amen.