(18) O that Ishmael . . . --For thirteen years Ishmael had been the "son of the house" (Genesis 15:3), and regarded probably as the true heir. Mingled then with Abraham's joy there was also the pain, natural to a father, of knowing that this transference of the promise to Sarah's child meant the deposition and disappointment of one who for so long had held the post of honour. Stoicism would have repressed this upright and natural feeling, but God hears and accepts the father's prayers; and while the birthright and religious pre-eminence is justly given to the son of the freewoman, there is a large earthly blessing for the handmaid's son.

Verse 18. - And Abraham said unto God, O that Ishmael might live before thee! Not implying that Abram was content with Hagar's child as the promised seed without waiting for Sarai s son (Jerome, Calvin, Kalisch); scarcely that he feared lest God might remove Ishmael by death now that Isaac had been promised (Wordsworth-); but probably that he desired that Ishmael might not only live and prosper (Bush), but share with Sarah s son in the blessings of the covenant (Keil, Longs, Rosenmüller, Murphy, 'Speaker's Commentary,' Inglis).

17:15-22 Here is the promise made to Abraham of a son by Sarai, in whom the promise made to him should be fulfilled. The assurance of this promise was the change of Sarai's name into Sarah. Sarai signifies my princess, as if her honour were confined to one family only; Sarah signifies a princess. The more favours God confers upon us, the more low we should be in our own eyes. Abraham showed great joy; he laughed, it was a laughter of delight, not of distrust. Now it was that Abraham rejoiced to see Christ's day; now he saw it and was glad, Joh 8:56. Abraham, dreading lest Ishmael should be abandoned and forsaken of God, put up a petition on his behalf. God gives us leave in prayer to be particular in making known our requests. Whatever is our care and fear, should be spread before God in prayer. It is the duty of parents to pray for their children, and the great thing we should desire is, that they may be kept in covenant with Him, and may have grace to walk before him in uprightness. Common blessings are secured to Ishmael. Outward good things are often given to those children of godly parents who are born after the flesh, for their parents' sake. Covenant blessings are reserved for Isaac, and appropriated to him.And Abraham said unto God,.... Being told he should have a son by Sarah, that should be his heir, he is concerned for Ishmael what would become of him; and who, being grown up, had doubtless a large share in his affections, and it is highly probable he began to think he was the promised seed, since he had lived to such an age, and had no other son, and Sarah was past bearing children: but now perceiving it would be otherwise, he puts up a petition for Ishmael, whom he did not neglect upon the promise of another, and to show his love to him, and regard for his welfare:

O that Ishmael might live before thee; he prays that his life might be preserved, and that it might be spent in the fear, worship, and service of God; so the Targum of Jonathan,"O that Ishmael might live and worship before thee,''and to the same sense Jarchi also; that he might enjoy the favour of God, his gracious presence and communion with him; that he might live a holy spiritual life here, acceptable and well pleasing to God, and possess eternal life hereafter: for we must take this prayer in as large a sense as we can suppose the heart of a father to be drawn forth in it for the good of his child; though it may greatly respect his sharing with the promised son in his blessings, and particularly regards the propagation of his offspring, or his living in his posterity at least; this was what the Lord took notice of, and answered him in.