Verses 1-21

Birth of Isaac (21:1-21)

When Isaac was born, Abraham circumcised him as commanded. In this way he demonstrated that Isaac was heir to God's covenant promises (21:1-7; cf. 17:9-14).

Ishmael made fun of the covenant family, as Sarah had feared. Being the son of a slave-girl, Ishmael had the right to inherit some of Abraham's wealth, but he could surrender this right in exchange for the freedom of himself and his mother. Sarah, determined that her son should be the sole heir, tried to persuade Abraham to force freedom upon Hagar and Ishmael by expelling them. Abraham hesitated to do this, because they had full rights to remain in his household. But God supported Sarah's suggestion. He promised to look after Hagar and Ishmael, and to make of Ishmael a great people; but his covenant was with Isaac (8-21).

Verses 22-34

Treaty with Abimelech (21:22-34)

Abraham had settled in the south of Canaan in Abimelech's territory and at Abimelech's invitation (see 20:15). Abimelech, however, was still wary of Abraham and fearful of the God whom Abraham worshipped. He suggested that Abraham and he make a treaty that would guarantee good relations between them (22-24). Abraham agreed to this, but at the same time he forced Abimelech to agree to return to him a well that Abimelech's herdsmen claimed as theirs. Abimelech publicly bound himself to the agreement by accepting from Abraham seven lambs as a witness (25-34). The place where the well was located became known as Beersheba, and Abraham later settled there (see 22:19).