They (Israel) were given so much truth. Paul speaks of the adoption, the glory, the covenants and the giving of the law. There were also the prophesies of Christ which as a whole they rejected.
Paul says that all of Abraham’s children are not the special seed but only through Isaac and Jacob, Christ being the special One. Paul brings out that God spoke of Jacob being first even in Rebekah’s womb. He knows all things even before we are born. For the sake of space I turn to the last verse. It is not of him (man) that wills nor him that runs but God that shows mercy. I am thankful for that from a former unworthy sinner.