God went up from Abraham - Ascended evidently before him, so that he had the fullest proof that it was no human being, no earthly angel or messenger, that talked with him; and the promise of a son in the course of a single year, at this set time in the next year, Genesis 17:21, which had every human probability against it, was to be the sure token of the truth of all that had hitherto taken place, and the proof that all that was farther promised should be fulfilled in its due time. Was it not in nearly the same way in which the Lord went up from Abraham, that Jesus Christ ascended to heaven in the presence of his disciples? Luke 24:51.

And he left off talking; with him,.... After he had finished all he had to say to him at this time. It was great condescension in the divine Being to talk with a creature; it was wonderful grace and kindness to make such promises to him, as he did, and indulge him with answers of prayer and communion with him; but the highest enjoyments of God here are not lasting; uninterrupted communion with him is reserved for another world:

and God went up from Abraham; from the earth, where he had been with Abraham, and ascended above him up to heaven, in a visible, and very likely in an human form, in which he descended: the Targums of Onkelos and Jonathan paraphrase it, "the glory of the Lord", the glorious Shechinah, the Lord of life and glory.

When God had finished His address and ascended again, Abraham immediately fulfilled the covenant duty enjoined upon him, by circumcision himself on that very day, along with all the male members of his house. Because Ishmael was 13 years old when he was circumcised, the Arabs even now defer circumcision to a much later period than the Jews, generally till between the ages of 5 and 13, and frequently even till the 13th year.

And he left off talking with him, and God went up from Abraham.

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.