Sarah, named Sarai until God renames her, is the wife of Abraham and the first of the four matriarchs of Israel. Her story in Genesis is dominated by a single tension: she is barren into old age, and yet the covenant promise to Abraham requires an heir of his own body.
The narrative works through that tension with painful realism. Despairing of bearing a child herself, Sarah gives her Egyptian servant Hagar to Abraham, who bears him Ishmael, and the resulting rivalry, Hagar's contempt and Sarah's harshness, drives Hagar into the wilderness. When at last three visitors announce that Sarah herself will bear a son within the year, she laughs in disbelief behind the tent door; the son, when he comes, is named Isaac (he laughs) in memory of it. After Isaac's birth she insists that Hagar and Ishmael be sent away, to secure her son's inheritance.
Twice in Genesis Abraham passes Sarah off as his sister before foreign kings, Pharaoh, and Abimelech of Gerar, to protect himself, and she is taken into their households and then restored, episodes that trouble readers and that the text presents without comment. She dies at Hebron, and Abraham buys the cave of Machpelah to bury her, the first family possession in the promised land.