One of the characteristics of Abraham’s faith is his ability to wait and to be patient—at least most of the time. Twenty-five years earlier God promised Abraham a son (chap. 12). Now that promise becomes reality (21:1–7) after some false hopes and false moves. Appropriately, and following an earlier directive, Abraham names the child Isaac, meaning “he laughs.” Who laughs? God? Isaac? Abraham? Then Abraham circumcises Isaac (21:4).

For a third time somebody laughs, and here it is Sarah (21:6–7). This is a joyful laughter, and her joy will be contagious.

How quickly festivities can turn into friction (21:8–21). Sarah sees Ishmael mocking Isaac after Isaac has been weaned (about three years). Actually the Hebrew word for “mocking” is “to laugh.” Ishmael was “Isaac-ing” Isaac. Paul’s choic…