[218] But when he prays that Ishmael may live, he does not despair of the birth of Isaac, as I have already said, but he believes in God; for it does not follow that what it is possible [158] for God to give, it is also possible for man to receive, since to God it is easy to give the most numerous and important benefits, but to us it is not easy to accept of the gifts which are proffered to us;