What does Genesis chapter 21 mean?Genesis 21 begins with the long-awaited birth of the son God had promised to Abraham and Sarah. This is the child through whom God would make of Abraham a great nation (Genesis 17:6–7). More recently, the Lord had promised both Abraham and Sarah that they would conceive and bear a son within a year's time. Both of them laughed (Genesis 17:17; Genesis 18:12). God said the name of their son would be Isaac, which means laughter (Genesis 17:19).
Now the time has come. The Lord visits Sarah. She and Abraham conceive, just as God said, just as He promised (Genesis 18:14). At the ages of 100 and 90 respectively, Abraham and Sarah become parents. Sarah bears Abraham a son, full of joy at the laughter He has brought to her (Genesis 21:1–7).
That joy sours, though, after Isaac is weaned. Sarah sees Abraham's son through Hagar, Ishmael, laughing. She seems to think this is directed at little Isaac. Ishmael is Abraham's firstborn son, born to him by Sarah's own Egyptian slave girl Hagar, at Sarah's insistence. Now though, Sarah furiously demands that Abraham cast Hagar and Ishmael out into the wilderness to eliminate any possibility that Hagar's son will share the inheritance with her Isaac (Genesis 21:8–10).
Abraham is greatly displeased at Sarah's demand since he is attached to Ishmael. The Lord, however, speaks to Abraham. Abraham's name and inheritance must pass to and through Isaac. The Lord assures Abraham He will still make a great nation of Ishmael, and so tells him to do what Sarah has asked (Genesis 21:11–13).
Abraham obeys and sends his slave wife and son into the wilderness with some bread and water. They soon run out of water, and Hagar puts her son under the shade of a bush to die. An angel calls to her from heaven, however. God has heard Ishmael's voice, and He will still make of Ishmael a great nation. Water is provided; Hagar and Ishmael survive. Ishmael grows up in the wilderness, becoming a great archer, and eventually marrying an Egyptian woman (Genesis 21:14–21).
After Hagar and Ishmael have gone, Abimelech, king of Gerar, approaches Abraham. In spite of the fact that Abraham's deception about Sarah being his wife nearly led to Abimelech's death, the king has noticed that God is with Abraham. He has respect for God's power and His blessing of all that Abraham does. Previously Abimelech has given to Abraham animals, servants, silver, and the land Abraham has been occupying. Now Abimelech would like to formalize their relationship, giving Abraham a permanent home in his region and becoming official allies (Genesis 21:22–24).
Abraham agrees to Abimelech's request to swear not to deceive him or his offspring ever again, and to deal kindly with him and his people. Abraham insists on including in their agreement the resolution of the ownership of a disputed well, one Abraham himself had dug. He gives seven additional lambs to Abimelech as a sign that the well does indeed belong to Abraham (Genesis 21:25–30).
After they both swear their oaths to bind the agreement, the place where they met is called Beersheba, which means "well of seven" or "well of the oath." It becomes an important place in Israel's history (Genesis 21:31–34).
As Genesis 21 concludes, Isaac has been born and Abraham owns a well in Canaan. The promises of God to make of him a great nation and to give to him possession of the entire land have begun to come true. Still ahead, however, is the greatest test of all Abraham has learned about God, a dire request which seems to threaten this promised son.