The Law · Chapter 21 of 50

Genesis 21

The LORD keeps His word and Sarah bears Isaac in her old age, and Abraham circumcises him at eight days. Sarah's joy turns to conflict when she sees Ishmael mocking, and she demands that Hagar and her son be cast out. God comforts Abraham, promising to make Ishmael a nation, and rescues Hagar and the boy in the wilderness. Abraham makes a covenant with Abimelech at Beersheba.

What happens in Genesis 21

The LORD visits Sarah as promised, and she conceives and bears Isaac in Abraham's old age. He circumcises the boy at eight days and names him Isaac, laughter, for Sarah says God has made her laugh. At Isaac's weaning feast, Sarah sees Ishmael mocking and demands Abraham cast out the bondwoman and her son. Grieved, Abraham obeys after God assures him the promise runs through Isaac, yet He will also make Ishmael a nation.

Hagar wanders in the wilderness of Beersheba, and when the water is gone she sets the child down to weep. God hears the boy, opens Hagar's eyes to a well, and promises to make him great. Meanwhile Abimelech, seeing God with Abraham, seeks an oath of peace. They settle a dispute over a well and make a covenant at Beersheba, where Abraham calls on the everlasting God.

Genesis 21 in context

The long awaited son finally arrives, fulfilling promises given as far back as Genesis 12 and 15 and renewed just chapters earlier. Isaac's birth sets up the tension between the child of promise and the child of Hagar, which Paul later reads as an allegory in Galatians 4.

Beersheba, well of the oath, becomes a key patriarchal site. The chapter also shows God's compassion reaching Hagar and Ishmael outside the chosen line.

Main themes of Genesis 21

Promise fulfilled in laughterAfter decades of waiting, God does exactly what He said at the set time. Sarah's laughter of doubt becomes laughter of joy, and the child is named Laughter. God's timing is not our own, but His word does not fail, and its fulfillment turns sorrow into delight.
God hears the outcastHagar and Ishmael, sent away and dying of thirst, are not beyond God's care. He hears the boy's voice and opens her eyes to water already near. Even those outside the covenant promise are seen and provided for by a compassionate God.
Two sons, two futuresThe child of promise and the child of the bondwoman cannot share the inheritance, yet both receive a future from God. Paul later reads this as flesh versus promise, freedom versus bondage, showing that God's blessing comes by His word, not by human striving.
This is part of the Law, the foundation of the whole story: creation, covenant, and a God who binds Himself to a people. As you read, watch for God's character and His promises, which all lead toward Christ.

Genesis 21 (KJV)

1And the LORD visited Sarah as he had said, and the LORD did unto Sarah as he had spoken. 2For Sarah conceived, and bare Abraham a son in his old age, at the set time of which God had spoken to him. 3And Abraham called the name of his son that was born unto him, whom Sarah bare to him, Isaac. 4And Abraham circumcised his son Isaac being eight days old, as God had commanded him. 5And Abraham was an hundred years old, when his son Isaac was born unto him. 6And Sarah said, God hath made me to laugh, so that all that hear will laugh with me. 7And she said, Who would have said unto Abraham, that Sarah should have given children suck? for I have born him a son in his old age. 8And the child grew, and was weaned: and Abraham made a great feast the same day that Isaac was weaned. 9And Sarah saw the son of Hagar the Egyptian, which she had born unto Abraham, mocking. 10Wherefore she said unto Abraham, Cast out this bondwoman and her son: for the son of this bondwoman shall not be heir with my son, even with Isaac. 11And the thing was very grievous in Abraham’s sight because of his son. 12And God said unto Abraham, Let it not be grievous in thy sight because of the lad, and because of thy bondwoman; in all that Sarah hath said unto thee, hearken unto her voice; for in Isaac shall thy seed be called. 13And also of the son of the bondwoman will I make a nation, because he is thy seed. 14And Abraham rose up early in the morning, and took bread, and a bottle of water, and gave it unto Hagar, putting it on her shoulder, and the child, and sent her away: and she departed, and wandered in the wilderness of Beersheba. 15And the water was spent in the bottle, and she cast the child under one of the shrubs. 16And she went, and sat her down over against him a good way off, as it were a bow shot: for she said, Let me not see the death of the child. And she sat over against him, and lift up her voice, and wept. 17And God heard the voice of the lad; and the angel of God called to Hagar out of heaven, and said unto her, What aileth thee, Hagar? fear not; for God hath heard the voice of the lad where he is. 18Arise, lift up the lad, and hold him in thine hand; for I will make him a great nation. 19And God opened her eyes, and she saw a well of water; and she went, and filled the bottle with water, and gave the lad drink. 20And God was with the lad; and he grew, and dwelt in the wilderness, and became an archer. 21And he dwelt in the wilderness of Paran: and his mother took him a wife out of the land of Egypt. 22And it came to pass at that time, that Abimelech and Phichol the chief captain of his host spake unto Abraham, saying, God is with thee in all that thou doest: 23Now therefore swear unto me here by God that thou wilt not deal falsely with me, nor with my son, nor with my son’s son: but according to the kindness that I have done unto thee, thou shalt do unto me, and to the land wherein thou hast sojourned. 24And Abraham said, I will swear. 25And Abraham reproved Abimelech because of a well of water, which Abimelech’s servants had violently taken away. 26And Abimelech said, I wot not who hath done this thing: neither didst thou tell me, neither yet heard I of it, but to day. 27And Abraham took sheep and oxen, and gave them unto Abimelech; and both of them made a covenant. 28And Abraham set seven ewe lambs of the flock by themselves. 29And Abimelech said unto Abraham, What mean these seven ewe lambs which thou hast set by themselves? 30And he said, For these seven ewe lambs shalt thou take of my hand, that they may be a witness unto me, that I have digged this well. 31Wherefore he called that place Beersheba; because there they sware both of them. 32Thus they made a covenant at Beersheba: then Abimelech rose up, and Phichol the chief captain of his host, and they returned into the land of the Philistines. 33And Abraham planted a grove in Beersheba, and called there on the name of the LORD, the everlasting God. 34And Abraham sojourned in the Philistines’ land many days.

Verses to carry from Genesis 21

“And the LORD visited Sarah as he had said, and the LORD did unto Sarah as he had spoken.”Genesis 21:1

“And God said unto Abraham, Let it not be grievous in thy sight because of the lad, and because of thy bondwoman; in all that Sarah hath said unto thee, hearken unto her voice; for in Isaac shall thy seed be called.”Genesis 21:12

“And God heard the voice of the lad; and the angel of God called to Hagar out of heaven, and said unto her, What aileth thee, Hagar? fear not; for God hath heard the voice of the lad where he is.”Genesis 21:17

Christian typology

How Genesis 21 points to Jesus

Isaac is the child of promise, born not by natural strength but by God's word at the appointed time, when Sarah's womb was long dead. Paul makes the pattern explicit: we, brethren, as Isaac was, are the children of promise, and he reads Hagar and Sarah as two covenants, one of slavery and one of freedom (Galatians 4:22-31). Isaac's supernatural birth foreshadows a greater promised Son, Jesus, whose coming likewise depended entirely on God's power and word, not on human ability.

And in the phrase in Isaac shall thy seed be called (Genesis 21:12) runs the line that leads to Christ. The God who heard a dying boy in the wilderness is the same God who hears every outcast and answers with living water.

Questions about Genesis 21

Why did God tell Abraham to listen to Sarah and send Ishmael away?

God had chosen Isaac as the child through whom the covenant promise would continue, saying, in Isaac shall thy seed be called (Genesis 21:12). The two sons could not share that inheritance without conflict. Yet God's command came with compassion, for He also promised to make Ishmael a great nation and personally cared for him in the desert. The hard choice served the promise while leaving no one abandoned.

What does Isaac's name teach us?

Isaac means laughter. Sarah once laughed in disbelief that she could bear a child in old age, but now she laughs in joy, saying God has made her to laugh (Genesis 21:6). The name marks the turn from doubt to delight, a permanent reminder that God does the impossible and that His fulfilled promises leave His people rejoicing rather than skeptical.

Reflection

Is there a promise you have waited on so long that hope has curdled into doubt? Sarah's story says God's set time still comes. And if you feel cast out like Hagar, thirsty and unseen, know that God hears the voice of the one wandering in the wilderness and opens eyes to water.

A prayer from Genesis 21

Faithful God, You keep Your word at the set time even when I have stopped expecting it. Turn my doubt into laughter, and when I feel like an outcast, open my eyes to the well of Your provision. I trust Your promise. Amen.
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