Genesis 17:20

20. And as for Ishmael. He here more clearly discriminates between the two sons of Abraham. For in promising to the one wealth, dignity, and other things pertaining to the present life, he proves him to be a son according to the flesh. But he makes a special covenant with Isaac, which rises above the world and this frail life: not for the sake of cutting Ishmael off from the hope of eternal life, but in order to teach him that salvation is to be sought from the race of Isaac, where it really dwells. We infers however, from this passage, that the holy fathers were by no means kept down to earth, by the promises of God, but rather were borne upwards to heaven. For God liberally and profusely promises to Ishmael whatever is desirable with respect to this earthly life: and yet He accounts as nothing all the gifts He confers on him, in comparison with the covenant which was to be established in Isaac. It therefore follow, that neither wealth, nor power, nor any other temporal gift, is promised to the sons of the Spirit, but an eternal blessing, which is possessed only by hope, in this world. Therefore, however we may now abound in delights, and in all good things, our happiness is still transient, unless by faith we penetrate into the celestial kingdom of God, where a greater and higher blessing is laid up for us.

It is however asked, whether Abraham had respect only to this earthly life when he prayed for his son? For this the Lord seems to intimate, when he declares that he had granted what Abraham asked, and yet only mentions the things we have recorded. But it was not God’s design to fulfill the whole wish of Abraham on this point; only he makes it plain that he would have some respect to Ishmael, for whom Abraham had entreated; so as to show that the fathers prayer had not been in vain. For he meant to testify that he embraced Abraham with such love, that, for his sake, he had respect to his whole race, and dignified it with peculiar benefits.