Genesis 21, Laughter

God has promised Abraham a son.  But that was some time ago....

Genesis 21:1-3, The birth of Isaac
Now the LORD was gracious to Sarah as he had said, and the LORD did for Sarah what he had promised. Sarah became pregnant and bore a son to Abraham in his old age, at the very time God had promised him. Abraham gave the name Isaac to the son Sarah bore him.

Suddenly, at the end of the description of barren women in Abimelech's harem, we have an announcement. Sarah is pregnant! In a few short lines, she has a son and they name him Isaac, as previously foretold.

Genesis 21:4-5, The circumcision of Isaac
When his son Isaac was eight days old, Abraham circumcised him, as God commanded him. Abraham was a hundred years old when his son Isaac was born to him.

"Isaac" means "he laughs", harkening back to Abraham's response in Genesis 17:17-19. Sarah finally has the child she had long wanted.

The chapter divisions in our Bible are artificial, created in medieval times.  If one were reading this in an old Hebrew scroll, the story of the infertility of Abimelech's harem would continue into this chapter without pause, sharply contrasted by the story of Sarah's pregnancy. They are all part of one common story about Sarah and promises of children and descendants. 

Isaac is circumcised at eight days old. This will become a standard timeline for those Jews who consistently practice circumcision. (Jesus, in the New Testament, was also circumcised after eight days, see Luke 2:21.)

Genesis 21:6-8, Laughter comes to Sarah

Sarah said, "God has brought me laughter, and everyone who hears about this will laugh with me." And she added, "Who would have said to Abraham that Sarah would nurse children? Yet I have borne him a son in his old age."

The child grew and was weaned, and on the day Isaac was weaned Abraham held a great feast.

Sarah uses the name Isaac to describe her reaction to her child. She has dreamed of this for decades and now laughs about this surprise blessing. Laughter will continue for a time as a theme of this passage.

Genesis 21:9-13, Sarah turns on Hagar

But Sarah saw that the son whom Hagar the Egyptian had borne to Abraham was mocking, and she said to Abraham, "Get rid of that slave woman and her son, for that slave woman's son will never share in the inheritance with my son Isaac."

The matter distressed Abraham greatly because it concerned his son.

But God said to him, "Do not be so distressed about the boy and your maidservant. Listen to whatever Sarah tells you, because it is through Isaac that your offspring will be reckoned. I will make the son of the maidservant into a nation also, because he is your offspring."

Sarah's joyful laughter is ruined by Hagar's mocking laughter. So Sarah attempts to remove Hagar and Ishmael, even though the birth of Hagar's child was her idea.

Genesis 21:14-16, Hagar and Ishmael are dismissed
Early the next morning Abraham took some food and a skin of water and gave them to Hagar. He set them on her shoulders and then sent her off with the boy. She went on her way and wandered in the desert of Beersheba.When the water in the skin was gone, she put the boy under one of the bushes. Then she went off and sat down nearby, about a bowshot away, for she thought, "I cannot watch the boy die." And as she sat there nearby, she began to sob.

The Septuagint (ancient Greek translation) has the child sobbing, not Hagar. This fits better with the next paragraph.

Genesis 21:17-21, God intervenes to save Ishmael

God heard the boy crying, and the angel of God called to Hagar from heaven and said to her, "What is the matter, Hagar? Do not be afraid; God has heard the boy crying as he lies there. Lift the boy up and take him by the hand, for I will make him into a great nation."

Then God opened her eyes and she saw a well of water. So she went and filled the skin with water and gave the boy a drink.

God was with the boy as he grew up. He lived in the desert and became an archer. While he was living in the Desert of Paran, his mother got a wife for him from Egypt. 

God intervenes to save Ishmael by pointing out a well of water nearby. God has great plans for Ishmael, even though he is not in the line of Israel.

Genesis 21:22-31, Treaty with Abimelech

At that time Abimelech and Phicol the commander of his forces said to Abraham, "God is with you in everything you do. Now swear to me here before God that you will not deal falsely with me or my children or my descendants. Show to me and the country where you are living as an alien the same kindness I have shown to you."

Abraham said, "I swear it."

Then Abraham complained to Abimelech about a well of water that Abimelech's servants had seized. But Abimelech said, "I don't know who has done this. You did not tell me, and I heard about it only today."

So Abraham brought sheep and cattle and gave them to Abimelech, and the two men made a treaty. Abraham set apart seven ewe lambs from the flock, and Abimelech asked Abraham, "What is the meaning of these seven ewe lambs you have set apart by themselves?"

He replied, "Accept these seven lambs from my hand as a witness that I dug this well."

So that place was called Beersheba, because the two men swore an oath there.

After the interlude about Sarah and Isaac, we return to the story of Abraham and Abimelech. Abimelech is aware that Abraham is protected by his God and pursues alliances.

The site of the treaty, Beersheba, will continue to appear throughout Old Testament history, eventually becoming one of the southernmost towns in the southern kingdom of Judah. (According to the NIV footnotes, "Beersheba" can mean "well of seven" or "well of the oath".)

Genesis 21: 32-34, Beersheba and the Eternal God

After the treaty had been made at Beersheba, Abimelech and Phicol the commander of his forces returned to the land of the Philistines. Abraham planted a tamarisk tree in Beersheba, and there he called upon the name of the LORD, the Eternal God. And Abraham stayed in the land of the Philistines for a long time.

Abraham stays for a time in the land of the Philistines, planting a tree and settling down. He worships by calling on God as "the eternal God".

Some Hebrew vocabulary

Our Hebrew word for the day is olam 

עוֹלָם

which means "forever" or "everlasting". It appears in Genesis 3:22 and Genesis 6:4, where its meaning is different. In the first passage, it means "forever"; in the second it means "from ancient times." In this chapter, in verse 33, it is part of God's name, representing an attribute of God, as one who is eternal, everlasting.

Some Random Thoughts

Chapters 12-14 and 21-22 have some striking parallels in the life of Abram/Abraham. I copy, below, a table from John Walton's Genesis commentary (p. 501) which list those parallels.

    Threat from foreign ruler                        12:10-20             20:1-18

    Division of the family                             13:1-13               21:8-21

    Granting of the promised blessing          13:14-17             21:1-7

    Agreement with a foreign ruler               14:1-24               21:22-34

    Heir crisis                                                15:1-4                 22:1-2

    Descendants as the stars                          15:5                    22:17

    Recognition of Abraham's faith                15:6                    22:12

    Sacrificial context                                    15:9-11              22:1-11

Abraham's life and covenant relationship with God has cycles. The next chapter will describe an intensive test of Abraham and a step higher in that relationship..

First published Jan 25, 2023; updated Jan 23, 2026