Genesis 21

Genesis 21 focuses on three key events in Abraham's life.

1. Birth of Isaac — As God promised, Sarah gives birth to Abraham's son Isaac when Abraham is 100 years old. Isaac's name means "laughter," reflecting Sarah's joy and initial disbelief that she would bear a child in her old age. Abraham circumcises Isaac on the eighth day as commanded by God.

2. Hagar and Ishmael's banishment — After Isaac is weaned, Sarah sees Ishmael (Abraham's firstborn son by Hagar) mocking Isaac. Sarah demands that Abraham send Hagar and Ishmael away. Though upset, Abraham obeys after God reassures him that Ishmael will also become a nation. Hagar and Ishmael nearly die in the wilderness until God provides water and promises that Ishmael will become a great nation. Ishmael grows up in the wilderness of Paran and becomes an archer.

3. Covenant with Abimelech — Abimelech, king of Gerar, recognizes God's favor on Abraham and proposes a treaty of peace between them. Abraham agrees but raises an issue about a well that Abimelech's servants had seized. They resolve the dispute, and Abraham plants a grove at Beersheba ("well of the sevenfold oath") to commemorate their covenant. Abraham continues to sojourn in Philistine territory.

The chapter shows the fulfillment of God's promise regarding Isaac, while also revealing His provision for Ishmael despite his not being the child of promise.