This chapter has three distinct sections. There is the birth of Isaac, a second and final departure of Hagar from Abraham’s clan, and a covenant that Abraham makes with Abimelech. These events center around God’s increasingly visible plan. As Abraham’s story progresses through this chapter, we are slowly seeing how God is beginning to fulfill the promises He made in Genesis 12.
Verses 1-7: Isaac
At long last, Abraham and Sarah have Isaac. Isaac’s birth occurs through the providence of God and in accordance with God’s instruction that every male be circumcised (Genesis 17). Abraham circumcises Isaac when he is eight days old. At the time of the birth, Abraham and Sarah were very advanced in age. Nevertheless, Sarah was a nursing mother. In verses 6-7, we witness Abraham and Sarah surprised and delighted to be present at the unlikely event of their healthy son: “And Sarah said, “God has made me laugh, and all who hear will laugh with me.” She also said, “Who would have said to Abraham that Sarah would nurse children? For I have borne him a son in his old age.””
Verses 8-21: Hagar/Ishmael
Abraham has a great feast to celebrate Isaac’s being weaned from nursing. During this feast, Sarah sees Hagar and Ishmael. Recall the story of Hagar giving birth to Ishmael in Genesis 16. Sarah has obviously remained displeased with Hagar as Hagar was able to conceive with Abraham when she was not. Sarah, to her discredit, has allowed this resentment to persist and perhaps even grow.
What happens next is the beginning of God’s promise to Hagar from Genesis 16:11-12. In that passage, a pregnant and despondent Hagar received a promise of her own: “And the Angel of the LORD said to her: “Behold, you are with child, And you shall bear a son. You shall call his name Ishmael, Because the LORD has heard your affliction. He shall be a wild man; His hand shall be against every man, And every man’s hand against him. And he shall dwell in the presence of all his brethren.””
Back to Genesis 22, when Sarah sees Hagar at the feast, and in particular when she sees Ishmael scoffing, she tells Abraham to cast out Hagar and Ishmael. Abraham is troubled by this, but God tells him to make it so. God is fulfilling the promise that Isaac will be the son through which the main promise is fulfilled, but a great nation will still come from Ishmael. Abraham sends them away into the wilderness with just a skin of water, which quickly runs out. Hagar perceives that she and Ishmael may soon die. Because she could not bear to see it, she puts Ishmael under a bush to die and she expects her own death is imminent.
But God hears Ishmael’s voice and provides a way for them both to be saved. Ishmael will go on to fulfill the promises that God made to Hagar. He lives in the Wilderness of Paran and has a wife that his mother procures for him from Egypt.
Verses 15-21 in Genesis 21 are an interesting parallel to the passage of Hagar alone in Genesis 16. In both passages, Hagar is alone and in peril, either physically or in danger of separation from God. In both cases, God saves Hagar to ensure that His promise will be fulfilled that Ishmael will be the beginning of a great nation. Through her actions in these situations, Hagar reveals that she is prone to run away or give up when faced with hardship. Although she seems to lean towards hopelessness, God saves her and Ishmael to make good on His promise. There is a grave and important lesson for us here: do not ever lose hope; if we obey and believe, God will make good on His promise to save us.
Verses 22-34: Abimelech
Abimelech is familiar to us now as a powerful king that respects the power of God and that has respect for Abraham too. Phichol, the army commander for Abimelech, asks Abraham to swear not to “deal falsely with me, with my offspring, or with my posterity; but that according to the kindness that I have done to you, you will do to me and to the land in which you have dwelt.” Abraham agrees. The influence of Abraham’s God had spread from Abimelech to the commander of his army.
Abraham takes the opportunity to address a well that he had dug that Abimelech’s people had apparently taken over. Abimelech, true to his character of respect for Abraham, expresses concern over the well and says that he was unaware of it. Abraham gives seven ewe lambs to Abimelech as a sign of a covenant to witness that it was indeed Abraham’s well. The chapter ends with Abraham and Abimelech solidifying the covenant at the newly named “Beersheba.” Abraham plants a tamarisk tree there and then prays to God. Abraham, having found favor in the leader of the land through God, stays in that area of Philistia for many days.
Although this chapter contains diverse elements, the thread of God’s involvement runs through all. Little by little, God is fulfilling His promises.