{That he should be the heir of the world} (	o kl(8872)onomon
auton einai kosmou). The articular infinitive (	o einai) with
the accusative of general reference in loose apposition with h(880a)epaggelia (the promise). But where is that promise? Not just  Ge
12:7 , but the whole chain of promises about his son, his
descendants like the stars in heaven, the Messiah and the
blessing to the world through him. In these verses ( 13-17 ) Paul
employs (Sanday and Headlam) the keywords of his gospel (faith,
promise, grace) and arrays them against the current Jewish
theology (law, works, merit).