Genesis 21: Isaac Born, Hagar Sent Away

Short answer: Genesis 21 recounts the birth of Isaac to Abraham and Sarah in their old age, fulfilling God's promise. It also describes Hagar and Ishmael's departure, God's rescue of them in the wilderness, and Abraham's treaty with Abimelech at Beersheba.

What Genesis 21 says

Genesis 21 opens with the long awaited fulfillment of God's promise. Yahweh visits Sarah, and she conceives and bears a son to Abraham in his old age, at the exact time God had spoken. Abraham names the boy Isaac and circumcises him on the eighth day, just as God commanded. Sarah marvels that God has made her laugh, and she anticipates that everyone who hears will laugh with her. She acknowledges the impossibility of anyone predicting she would nurse a child in Abraham's old age. The child grows and is weaned, and Abraham celebrates with a great feast. The text emphasizes that God did exactly what He said, highlighting His faithfulness to His word.

The joy of Isaac's birth is soon overshadowed by conflict. Sarah sees Ishmael, the son of Hagar the Egyptian, mocking. She demands that Abraham cast out the servant woman and her son, insisting that Ishmael will not share the inheritance with Isaac. Abraham is deeply distressed because of his son Ishmael. God intervenes, telling Abraham not to be grieved, but to listen to Sarah, for through Isaac shall Abraham's offspring be named. Yet God also promises to make a nation of Ishmael because he too is Abraham's child. Abraham rises early, gives Hagar bread and water, and sends her away with the boy. Hagar wanders in the wilderness of Beersheba, and when the water runs out, she places the child under a shrub and sits a bowshot away, weeping, unable to watch him die.

In the wilderness, God hears the voice of the boy. The angel of God calls to Hagar from heaven, asking what troubles her and telling her not to fear, for God has heard the boy's voice. The angel instructs her to lift up the boy and hold him, promising to make him a great nation. God opens her eyes, and she sees a well of water. She fills the container and gives the boy a drink. God is with Ishmael as he grows; he lives in the wilderness of Paran and becomes an archer. His mother gets him a wife from Egypt. Meanwhile, Abimelech and Phicol, his army captain, approach Abraham, acknowledging that God is with him. They ask Abraham to swear an oath of kindness, and Abraham agrees. When Abraham complains about a well seized by Abimelech's servants, Abimelech pleads ignorance. They make a covenant, and Abraham sets apart seven ewe lambs as a witness that he dug the well. The place is named Beersheba. Abraham plants a tamarisk tree and calls on the name of Yahweh, the Everlasting God. He lives as a foreigner in the land of the Philistines many days.

The chapter closes with Abraham's covenant with Abimelech at Beersheba. After the emotional upheaval of Hagar and Ishmael's departure, Abraham settles a dispute over a well and establishes a peaceful agreement with the local ruler. The seven ewe lambs serve as a legal witness that Abraham dug the well, and the name Beersheba commemorates the oath sworn there. Abraham plants a tamarisk tree, a sign of permanence and worship, and calls on the name of Yahweh, the Everlasting God. The text notes that Abraham lived as a foreigner in the land of the Philistines many days. This final scene underscores God's continued presence with Abraham, even as he navigates relationships with neighboring peoples. It also shows Abraham's commitment to worship and to securing a peaceful existence for his household.

Verses that carry the chapter

• “Yahweh visited Sarah as he had said, and Yahweh did to Sarah as he had spoken.” (Genesis 21:1) — This verse anchors the entire chapter in God's prior promise. It explicitly states that Yahweh visited Sarah and did for her exactly what He had spoken, demonstrating that God's word is reliable and His timing is perfect.
• “God said to Abraham, “Don’t let it be grievous in your sight because of the boy, and because of your servant. In all that Sarah says to you, listen to her voice. For your offspring will be named through Isaac.” (Genesis 21:12) — God clarifies that Abraham's offspring will be named through Isaac, not Ishmael. This establishes the line of promise and sets the stage for the covenant to continue through Isaac, even as God also promises to bless Ishmael.
• “God heard the voice of the boy. The angel of God called to Hagar out of the sky, and said to her, “What troubles you, Hagar? Don’t be afraid. For God has heard the voice of the boy where he is.” (Genesis 21:17) — God hears the voice of the boy Ishmael and sends His angel to comfort Hagar. This reveals God's compassion for the outcast and His faithfulness to the promise He made to Abraham regarding Ishmael.
• “Abraham planted a tamarisk tree in Beersheba, and called there on the name of Yahweh, the Everlasting God.” (Genesis 21:33) — Abraham plants a tamarisk tree and calls on the name of Yahweh, the Everlasting God. This act of worship in Beersheba shows Abraham's continued devotion and recognition of God's eternal nature.

Gospel connection

Genesis 21 points forward to the gospel by showing God's faithfulness to His promise. Isaac's birth is a miraculous fulfillment of God's word, just as the coming of Jesus was the fulfillment of God's promises to Israel. The casting out of Hagar and Ishmael prefigures the distinction between the children of promise and the children of the flesh, a theme Paul develops in Galatians. Yet God's care for Hagar and Ishmael reveals His mercy extends beyond the chosen line. Ultimately, the chapter reminds us that God keeps His covenant and provides salvation through the promised offspring, Jesus Christ, who is the true heir of Abraham.

Application

This chapter invites us to trust God's timing and faithfulness, even when His promises seem delayed. Like Abraham and Sarah, we may wait many years for God to act, but He does what He says. We also learn to release our own plans and trust God's sovereign choice, as Abraham had to send Ishmael away. When we face wilderness seasons, like Hagar, we can cry out to God, who hears and provides. Finally, we are called to live peaceably with others, as Abraham did with Abimelech, and to worship God as the Everlasting God in every place.

Biblical fidelity check

The chapter does not explain why Sarah demanded Hagar and Ishmael be cast out beyond Ishmael's mocking. It does not specify the nature of the mocking or Ishmael's age. It does not record Abraham's emotional state beyond grief, nor does it detail Hagar's thoughts after the angel's visit. The text does not state that Ishmael was excluded from God's blessing; rather, God promises to make him a nation. It also does not clarify the exact location of Beersheba or the duration of Abraham's stay in the Philistine land. These silences remind us to avoid speculation beyond what is written.

Questions for study

1. How does Sarah's laughter in verse 6 reflect her earlier doubt, and what does it show about God's ability to bring joy out of impossibility?
2. Why do you think Abraham was so distressed about sending Ishmael away, and how did God address his concern?
3. What does Hagar's experience in the wilderness teach us about God's care for those who are marginalized or forgotten?
4. How does the covenant between Abraham and Abimelech demonstrate God's blessing on Abraham in the eyes of others?
5. What can we learn from Abraham's worship at Beersheba, and how might we cultivate a similar practice of calling on the Lord in our own lives?

Keep reading

Related studies: Genesis 10 Bible Study, Genesis 11 Bible Study, Genesis 12 Bible Study, Genesis 13 Bible Study.

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FAQ

Why did Sarah want Hagar and Ishmael sent away?

Sarah saw Ishmael mocking and feared he would share in Isaac's inheritance. She insisted that the son of the servant would not be heir with her son.

Did God abandon Ishmael in the wilderness?

No, God heard the boy's voice and sent His angel to Hagar, promising to make Ishmael a great nation. God opened her eyes to a well of water, and He was with Ishmael as he grew.

What is the significance of Beersheba in this chapter?

Beersheba is where Abraham and Abimelech made a covenant and swore an oath. Abraham set apart seven ewe lambs as a witness that he had dug the well, and he worshiped Yahweh there.