John Gill's Exposition of the Whole Bible
Genesis 21 - Introduction
INTRODUCTION TO GENESIS 21
This chapter gives an account of the conception, birth, circumcision, and weaning of Isaac, Genesis 21:1; of the mocking of Ishmael, and of the casting out of him and his mother from Abraham's house, at the request of Sarah, which, though grievous to Abraham, he complied with at the direction of God, Genesis 21:9; of the provision Abraham made for their departure, and of the supply they met with in the wilderness from God, where Ishmael was brought up, and where he married,
Genesis 21:14; and of a covenant between Abraham and Abimelech, king of Gerar, Genesis 21:22; and of Abraham's planting a grove, and calling on the name of the Lord, Genesis 21:33; and the chapter is closed with this observation, that Abraham sojourned in the land of the Philistines many days, Genesis 21:34.