Genesis 17:21

21 But I will set up my covenant with Isaac, who will be born to Sarah at this time next year.

Genesis 17:21 Meaning and Commentary

Genesis 17:21

But my covenant will one establish with Isaac
The covenant of circumcision; for though Ishmael was circumcised, and his posterity practised that rite, yet it was not enjoined them of God; nor was it to them, or served the same purpose as to the Israelites; and particularly the promise of the land of Canaan, made in that covenant, belonged only to the posterity of Isaac, and to those only in the line of Jacob, and especially that of the Messiah springing from him, which circumcision had a respect unto:

whom Sarah shall bear unto thee, at this set time, in the next year:
that is, at the end of nine months, which is the set time a woman goes with child.

Genesis 17:21 In-Context

19 But God said, "No, your wife Sarah will give birth to a son for you, and you will name him Isaac. I will set up my covenant with him and with his descendants after him as an enduring covenant.

20 As for Ishmael, I've heard your request. I will bless him and make him fertile and give him many, many descendants. He will be the ancestor of twelve tribal leaders, and I will make a great nation of him.

21 But I will set up my covenant with Isaac, who will be born to Sarah at this time next year.

22 When God finished speaking to him, God ascended, leaving Abraham alone.

23 Abraham took his son Ishmael, all those born in his household, and all those purchased with his silver—that is, every male in Abraham's household—and he circumcised the flesh of their foreskins that same day, just as God had told him to do.