Genesis 21
1 Yahweh visited Sarah as he had said, and Yahweh did to Sarah as he had spoken. 2 Sarah conceived, and bore Abraham a son in his old age, at the set time of which God had spoken to him. 3 Abraham called his son who was born to him, whom Sarah bore to him, Isaac.
4 Abraham circumcised his son Isaac when he was eight days old, as God had commanded him. 5 Abraham was one hundred years old when his son Isaac was born to him.
6 Sarah said, “God has made me laugh. Everyone who hears will laugh with me.” 7 She said, “Who would have said to Abraham, that Sarah would nurse children? For I have borne him a son in his old age.”
8 The child grew, and was weaned. Abraham made a great feast on the day that Isaac was weaned. 9 Sarah saw the son of Hagar the Egyptian, whom she had borne to Abraham, mocking. 10 Therefore she said to Abraham, “Cast out this servant and her son; for the son of this servant will not be heir with my son, Isaac.”
11 The thing was very grievous in Abraham’s sight on account of his son. 12 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. 13 Also of the son of the servant I will make a nation, because he is your offspring.”
14 Abraham rose up early in the morning, and took bread and a container of water, and gave it to Hagar, putting it on her shoulder, and the boy, and sent her away. She departed, and wandered in the wilderness of Beersheba.
15 The water in the container was spent, and she cast the boy under one of the shrubs. 16 She went, and sat down opposite him, a good way off, about a bow shot away. For she said, “Don’t let me see the death of the child.” She sat opposite him, and lifted up her voice, and wept.
17 God heard the voice of the boy. God’s angel 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. 18 Get up, lift up the boy, and hold him in your hand. For I will make him a great nation.”
19 God opened her eyes, and she saw a well of water. She went, filled the container with water, and gave the boy a drink. 20 God was with the boy, and he grew. He lived in the wilderness, and became an archer. 21 He lived in the wilderness of Paran. His mother took a wife for him out of the land of Egypt.
22 At that time Abimelech and Phicol the captain of his army spoke to Abraham, saying, “God is with you in all that you do. 23 Now therefore swear to me here by God that you will not deal falsely with me, nor with my son, nor with my son’s son. But according to the kindness that I have done to you, you shall do to me, and to the land in which you have lived as a foreigner.”
24 Abraham said, “I will swear.”
25 Abraham complained to Abimelech because of a water well, which Abimelech’s servants had violently taken away. 26 Abimelech said, “I don’t know who has done this thing. You didn’t tell me, neither did I hear of it, until today.”
27 Abraham took sheep and cattle, and gave them to Abimelech. Those two made a covenant. 28 Abraham set seven ewe lambs of the flock by themselves. 29 Abimelech said to Abraham, “What do these seven ewe lambs which you have set by themselves mean?”
30 He said, “You shall take these seven ewe lambs from my hand, that it may be a witness to me, that I have dug this well.” 31 Therefore he called that place Beersheba, because they both swore an oath there.
32 So they made a covenant at Beersheba. Abimelech rose up with Phicol the captain of his army, and they returned into the land of the Philistines.
33 Abraham planted a tamarisk tree in Beersheba, and called there on the name of Yahweh, the Everlasting God. 34 Abraham lived as a foreigner in the land of the Philistines many days.
Commentary
Overview
Genesis 21 records the long-awaited fulfillment of God's promise to Abraham and Sarah. After years of waiting, uncertainty, and human attempts to accomplish the promise through their own plans, Isaac is finally born at the exact time God had appointed. The chapter is filled with both joy and sorrow: Sarah celebrates the birth of the promised son, while Hagar and Ishmael are sent into the wilderness. Through both stories, Scripture reveals that God is faithful to His covenant and compassionate toward those in distress.
The chapter begins by emphasizing that the Lord acted “as He had said” and “as He had promised.” Isaac's birth is not presented as an achievement of Abraham and Sarah but as the direct fulfillment of God's word. Abraham is one hundred years old, and Sarah has passed the natural age of childbearing, making it unmistakably clear that the child exists because of divine power. Abraham names him Isaac and circumcises him on the eighth day, demonstrating obedience to the covenant sign God established in Genesis 17.
Sarah's laughter, which had once expressed doubt, is transformed into wonder and joy. Isaac's name means “he laughs,” permanently reminding the family that God had turned an apparently impossible promise into a cause for celebration. Everyone who hears of the birth will share in Sarah's amazement. Her response demonstrates that God's fulfilled promises often transform fear, shame, and unbelief into testimony and praise.
When Isaac is weaned, Abraham holds a great feast, but the celebration is interrupted by conflict involving Ishmael. Sarah sees Hagar's son mocking Isaac and demands that Hagar and Ishmael be sent away. Her response reflects genuine concern about the covenant inheritance, but it also exposes the painful consequences of the decision made years earlier in Genesis 16. Scripture does not hide the grief produced when impatience and human manipulation become entangled with family relationships.
Abraham is deeply distressed because Ishmael is also his son. God nevertheless tells him to listen to Sarah, making clear that the covenant line will continue through Isaac. This distinction does not mean that Ishmael is forgotten or without value. God promises to make him into a nation because he is Abraham's offspring. The chapter therefore distinguishes between the particular covenant purpose carried through Isaac and the broader mercy God extends to Ishmael.
In the wilderness of Beersheba, Hagar's water runs out, and she withdraws because she cannot bear to watch her son die. At this moment of complete helplessness, God hears the boy and speaks to Hagar through His angel. The name Ishmael means “God hears,” and the Lord once again proves faithful to that name. He opens Hagar's eyes to a well of water, renews His promise concerning Ishmael, and preserves both mother and son. What appeared to be the end of their story becomes the beginning of God's continued provision.
Ishmael grows up under God's care, becomes an archer, and settles in the wilderness of Paran. Although he is not the son through whom the covenant promise will continue, Scripture explicitly states that God is with him. This detail demonstrates that divine election for a particular redemptive purpose does not eliminate God's compassion for others. The Lord remains attentive to people who may appear displaced, overlooked, or outside the central line of the biblical narrative.
The final portion of the chapter records a covenant between Abraham and Abimelech. Abimelech recognizes that God is with Abraham in everything he does and seeks a peaceful agreement with him. Abraham also addresses the seizure of a well, and the dispute is resolved publicly through an oath and the gift of seven ewe lambs. The place is called Beersheba, a name connected with both the well and the oath. Abraham is still a foreigner in the land, but surrounding rulers are beginning to recognize God's blessing upon him.
Genesis 21 closes with Abraham planting a tamarisk tree and calling upon the name of the Lord, the Everlasting God. This title emphasizes that the God who made promises decades earlier remains faithful across every season and generation. Abraham has received the promised son but not yet the full inheritance of the land. He therefore continues to live by faith between promises already fulfilled and promises still awaiting completion.
Key Themes
Notable Verses
Genesis 21:1–3 records Isaac's birth and repeatedly emphasizes that God fulfilled exactly what He had promised.
Genesis 21:6–7 describes Sarah's laughter being transformed from disbelief into joyful testimony.
Genesis 21:12–13 identifies Isaac as the covenant son while also promising that Ishmael will become a nation.
Genesis 21:17–20 shows God hearing Ishmael, providing water in the wilderness, and remaining with him as he grows.
Genesis 21:22–34 records Abraham's covenant at Beersheba and his worship of the Lord as the Everlasting God.
Reflection and Application
Genesis 21 encourages believers to trust God's timing even when His promises appear delayed. Abraham and Sarah waited many years for Isaac, and their earlier impatience produced painful consequences. Yet their failures did not prevent God from doing what He had promised. The chapter calls believers to resist the temptation to force outcomes through fear or human manipulation and instead to rely upon the wisdom, power, and timing of the Everlasting God.
The chapter also offers comfort to those who feel forgotten or cast aside. Hagar and Ishmael entered the wilderness with few resources, but they were never beyond God's sight or hearing. The Lord provided for them and gave their story a future. Isaac's miraculous birth also points forward to the greater promised Son, Jesus Christ, the ultimate offspring of Abraham through whom blessing comes to all nations. Through Christ, believers become children of promise and receive an inheritance secured not by human effort but by God's faithful grace.