21:1-7 Who could believe that Abraham would have a son at 100 years of age—and live to raise him to adulthood? But doing the impossible is everyday business for God. Our big problems won’t seem so impossible if we let God handle them.
21:7 After repeated promises, a visit by two angels, and the appearance of the Lord himself, Sarah finally cried out with surprise and joy at the birth of her son. Because of her doubt, worry, and fear, she had forfeited the peace she could have felt in God’s wonderful promise to her. The way to bring peace to a troubled heart is to focus on God’s promises. Trust him to do what he says.
21:18 What happened to Ishmael, and who are his descendants? Ishmael became ruler of a large tribe or nation. The Ishmaelites were nomads living in the wilderness of Sinai and Paran, south of Israel. One of Ishmael’s daughters married Esau, Ishmael’s nephew (28:9). The Bible pictures the Ishmaelites as hostile to Israel and to God (Psalm 83:5, 6).
21:31 Beer-sheba, the southernmost city of Israel, lay on the edge of a vast wilderness that stretched as far as Egypt to the southwest and Mount Sinai to the south. The phrase “from Dan even to Beer-sheba” was often used to describe the traditional boundaries of the Promised Land (2 Chronicles 30:5). Beer-sheba’s southern location and the presence of several wells in the area may explain why Abraham settled there. Beer-sheba was also the home of Isaac, Abraham’s son.