Besides, the promise that he should possess the world, was not made to Abraham, or to his posterity in consideration of the law, but with regard to the righteousness by faith.

for if they only who are of the law have right of possession, faith is made useless, and the promise becomes of no effect.

therefore the inheritance is of faith, that it might be meerly of favour, to the end the promise might be assured to all his posterity, not to that part only who have the law, but to that also who have the faith of Abraham, the father of us all, as it is written,

he was not incredulously diffident of the divine promise; but was strong in faith, and did honour to God,

However, the divine promise cannot but have its effect. for they are not the whole of Israel, who are descended from Israel:

that is, the children by natural descent are not thereby the children of God: but the children of the promise are alone considered as his posterity.

for the words of the promise run thus, "at this time I will come, and Sara shall have a son."