Grafted in

But God is grafting Gentiles not into the tree (Israel) but into the root, whose richness sustains both natural and unnatural branches, both Jews and Gentiles. Thus, for Paul, heritage is created by grace: offspring are born by promise to be children of God (9:8). It is because Israel was formed in this way from the beginning that it is first in time, with a “natural” afliliation to divine mercy. Gentiles are brought into relation not to an ethnic deity … but to the God of whom Israel is a product and a witness.—J. M. G. Barclay, Paul and the Gift, 551n75 (emphasis original)