God destroys Sodom and Gomorrah, Lot lives with his daughters, Abraham lies to Abimelech about Sarah, and Isaac is born: Genesis 18–21

Sarah’s first response to a promise of a baby in her old age was to laugh in disbelief. When the baby came along, the name kept the laughter going, but now with delight in a promise fulfilled:

^{Genesis 21:6–7} And Sarah declared, “God has brought me laughter. All who hear about this will laugh with me. Who would have said to Abraham that Sarah would nurse a baby? Yet I have given Abraham a son in his old age!”