Genesis 17:21

21 Forsooth I shall make my covenant with Isaac, whom Sarah shall child to thee in this time in the tother year. (But I shall make my covenant with Isaac, whom Sarah shall bear for thee at this same 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 And the Lord said to Abraham, Sarah, thy wife, shall bear a son to thee, and thou shalt call his name Isaac, and I shall make my covenant with him into everlasting bond of peace, and to his seed after him; (And the Lord said to Abraham, No, thy wife Sarah shall bear a son for thee, and thou shalt call his name Isaac, and I shall make my covenant with him, and his descendants after him, yea, an everlasting covenant;)

20 also on Ishmael I have heard thee, lo! I shall bless him, and I shall increase (him), and I shall multiply him greatly; he shall engender twelve dukes, and I shall make him into a great folk. (and regarding Ishmael, I have heard thee, lo! I shall bless him, and I shall increase him, and I shall greatly multiply him; he shall beget twelve princes, and I shall make him into a great nation.)

21 Forsooth I shall make my covenant with Isaac, whom Sarah shall child to thee in this time in the tother year. (But I shall make my covenant with Isaac, whom Sarah shall bear for thee at this same time next year.)

22 And when the word of the speaker with him was ended (And when he was finished speaking), God ascended from Abraham.

23 Forsooth Abraham took Ishmael, his son, and all the born servants of his house, and all which he had bought, all the males of all men of his house, and circumcised the flesh of their rod(s), anon in that day, as the Lord commanded to him. (Then Abraham took his son Ishmael, and all the slaves born in his household, and all the slaves he had bought, yea, all the males of his household, and at once circumcised the flesh of their rods on that day, as the Lord had commanded him.)