I. Introduction
A. Transition from the events in Genesis 20, specifically Abraham’s encounter with Abimelech in Gerar
B. Introduction to the narrative of the birth of Isaac and the departure of Hagar and Ishmael in Genesis 21
II. The Birth of Isaac
A. Verses 1-2: God fulfills His promise to Abraham and Sarah, and Sarah gives birth to a son named Isaac
B. Verse 3: Abraham circumcises Isaac on the eighth day, as God had commanded
III. Conflict Between Sarah and Hagar
A. Verses 8-10: Isaac’s weaning celebration triggers conflict between Sarah and Hagar, as Sarah sees Ishmael mocking Isaac
B. Verses 11-13: Sarah demands that Abraham send away Hagar and Ishmael, expressing concern for Isaac’s inheritance
C. Verses 14-16: Abraham is distressed but God reassures him, promising to make Ishmael a great nation
IV. Hagar and Ishmael’s Departure
A. Verses 14-16: Abraham provides Hagar with bread and water, and she and Ishmael journey into the wilderness of Beersheba
B. Verses 17-19: Hagar and Ishmael run out of water, but God hears their cry and provides a well for them
V. Abraham’s Covenant with Abimelech
A. Verses 22-24: Abraham makes a covenant with Abimelech, confirming their agreement regarding a well of water
B. Verses 25-34: Abraham plants a tamarisk tree and calls upon the name of the Lord, and he dwells in the land of the Philistines for many days
VI. Conclusion
A. Summary of the events in Genesis 21
B. Transition to the subsequent chapters and the further development of the narrative
Note: This outline provides a general structure of Genesis 21, focusing on the birth of Isaac, the conflict between Sarah and Hagar, the departure of Hagar and Ishmael, and Abraham’s covenant with Abimelech. It highlights the fulfillment of God’s promise, the tensions within Abraham’s household, and the provision and protection provided by God. The actual chapter contains additional details, dialogues, and interactions that are not included in this outline.