TheoMaps

Act III · Promise

Genesis 21: Isaac born, Ishmael sent away

Isaac is born as promised, and Ishmael is sent away, for through Isaac Abraham's offspring will be reckoned.

Chapter 21 of 5034 verses3 sectionsBSB

Where Genesis 21 sits

Genesis66 books · 1,189 chaptersRevelation
In the story
Act III, Promise: Genesis 12–50; Job
In the Bible
Old Testament · The Law · chapter 21 of 50 in Genesis
In Genesis
Terah's line: Abraham, 11:27–25:11 · part of One family
Before
Genesis 20: Abraham in Gerar
After
Genesis 22: The LORD Will Provide

Genesis 21 summary

The LORD attends to Sarah as He said, and at a hundred Abraham has a son, Isaac, circumcised on the eighth day, while Sarah rejoices that God has made her laugh. At the weaning feast Ishmael mocks, and Sarah demands that the slave woman and her son be expelled; God tells Abraham to listen, for through Isaac his offspring will be reckoned, and promises to make Ishmael a nation. In the wilderness God hears the boy, shows Hagar a well, and is with him; then Abimelech seeks a covenant, Abraham settles a dispute over a well, names Beersheba, and calls on the LORD, the Eternal God.

Genesis 21 in context

Speaking
Moses, narrating; Sarah, God, the angel of God, Abimelech and Abraham speak
Written for
Israel, children of the promise through Isaac, learning that God's word, not human effort, brings the heir
Around it
Fulfills the promise of chs. 17–18 after the danger in Gerar (ch. 20); the test of Isaac follows (ch. 22)

How Genesis 21 points to Christ

Paul reads Hagar and Sarah as two covenants: the children of the free woman are children of promise, as believers in Christ are (Gal 4:22–31); “through Isaac your offspring will be reckoned” (Rom 9:7–8)

The sections of Genesis 21

  1. The LORD did as He had promised

    The LORD attends to Sarah as promised, and she bears Isaac, circumcised on the eighth day; God has made her laugh.

    21:1–7
  2. Expel the slave woman

    Hagar and Ishmael are sent away, for through Isaac the offspring will be reckoned, but God hears the boy and preserves him.

    21:8–21
  3. The covenant at Beersheba

    Abraham makes a sworn covenant with Abimelech at Beersheba and calls on the name of the LORD, the Eternal God.

    21:22–34

Read Genesis 21

The Birth of Isaac

1Now the LORD attended to Sarah as He had said, and the LORD did for Sarah what He had promised. 2So Sarah conceived and bore a son to Abraham in his old age, at the very time God had promised.

3And Abraham gave the name Isaac to the son Sarah bore to him. 4When his son Isaac was eight days old, Abraham circumcised him, as God had commanded him. 5Abraham was a hundred years old when his son Isaac was born to him.

6Then Sarah said, “God has made me laugh, and everyone who hears of this will laugh with me.” 7She added, “Who would have told Abraham that Sarah would nurse children? Yet I have borne him a son in his old age.”

8So the child grew and was weaned, and Abraham held a great feast on the day Isaac was weaned.

Sarah Turns against Hagar

9But Sarah saw that the son whom Hagar the Egyptian had borne to Abraham was mocking her son, 10and she said to Abraham, “Expel the slave woman and her son, for the slave woman’s son will never share in the inheritance with my son Isaac!”

11Now this matter distressed Abraham greatly because it concerned his son Ishmael. 12But God said to Abraham, “Do not be distressed about the boy and your maidservant. Listen to everything that Sarah tells you, for through Isaac your offspring will be reckoned. 13But I will also make a nation of the slave woman’s son, because he is your offspring.”

14Early in the morning, Abraham got up, took bread and a skin of water, put them on Hagar’s shoulders, and sent her away with the boy. She left and wandered in the Wilderness of Beersheba. 15When the water in the skin was gone, she left the boy under one of the bushes. 16Then she went off and sat down nearby, about a bowshot away, for she said, “I cannot bear to watch the boy die!” And as she sat nearby, she lifted up her voice and wept.

17Then God heard the voice of the boy, and the angel of God called to Hagar from heaven, “What is wrong, Hagar? Do not be afraid, for God has heard the voice of the boy where he lies. 18Get up, lift up the boy, and take him by the hand, for I will make him into a great nation.” 19Then 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.

20And God was with the boy, and he grew up and settled in the wilderness and became a great archer. 21And while he was dwelling in the Wilderness of Paran, his mother got a wife for him from the land of Egypt.

The Covenant at Beersheba

22At that time Abimelech and Phicol the commander of his army said to Abraham, “God is with you in all that you do. 23Now, therefore, swear to me here before God that you will not deal falsely with me or my children or descendants. Show to me and to the country in which you reside the same kindness that I have shown to you.”

24And Abraham replied, “I swear it.”

25But when Abraham complained to Abimelech about a well that Abimelech’s servants had seized, 26Abimelech replied, “I do not know who has done this. You did not tell me, so I have not heard about it until today.”

27So Abraham brought sheep and cattle and gave them to Abimelech, and the two men made a covenant. 28Abraham separated seven ewe lambs from the flock, 29and Abimelech asked him, “Why have you set apart these seven ewe lambs?”

30He replied, “You are to accept the seven ewe lambs from my hand as my witness that I dug this well.” 31So that place was called Beersheba, because it was there that the two of them swore an oath. 32After they had made the covenant at Beersheba, Abimelech and Phicol the commander of his army got up and returned to the land of the Philistines.

33And Abraham planted a tamarisk tree in Beersheba, and there he called upon the name of the LORD, the Eternal God. 34And Abraham resided in the land of the Philistines for a long time.

Berean Standard Bible, 34 verses. The BSB is in the public domain.

Also in Terah's line: Abraham

Places

  • Beersheba
  • Paran
  • Egypt

Read alongside

  • Galatians 4:28–31 Paul quotes 21:10: expel the slave woman and her son.
  • Hebrews 11:11–12 By faith Sarah, barren and past age, was enabled to conceive.
  • Genesis 26:33 Isaac renews the name Beersheba.

How Genesis 21 connects

  • The Seed Line · Genesis 21:12 · The line of promise is narrowed to Isaac. (Romans 9:7–8; Hebrews 11:18)
  • Promise · Genesis 21:12, kept in Romans 9:7–8; Hebrews 11:18
  • Promise · Genesis 21:13, kept in Genesis 25:12–16
  • Type · Hagar the slave woman and her son born according to the flesh, expelled pictures The covenant from Sinai that bears children into slavery, set beside the free children of promise (Galatians 4:22–31)

Doctrines Genesis 21 teaches

Questions on Genesis 21

  1. Which line in 21:12 tells whose line will carry the promise?

    Show the answer

    “Through Isaac your offspring will be reckoned” (21:12). Ishmael will also become a nation (21:13), but the promised line runs through Isaac, Sarah’s son.

  2. Where does Abraham call on “the Eternal God”?

    Show the answer

    At Beersheba, after his sworn covenant with Abimelech: Abraham plants a tamarisk tree there and calls on the name of the LORD, the Eternal God (21:31–33).

Genesis is open in full

Everything on this page is in the free app, as is all of Genesis. TheoMaps Plus opens the other 65 books the same way, with the map, Challenges and Step Inside.

Written and reviewed by AJ Reyes. Reviewed . How we write the notes

Sources for these notes (5)
  • The Reformation Heritage KJV Study Bible, ed. Joel R. Beeke
  • The Reformation Study Bible (ESV), ed. R. C. Sproul
  • Notes on Genesis, Thomas L. Constable
  • Chiasmus in the Book of Genesis (lecture handout), Gary A. Rendsburg
  • A Discourse of the Covenants, Nehemiah Coxe (1681)