Son of Abraham and father of Esau and Jacob. The principal stories about Isaac are found in Genesis 21–28. Isaac is a more shadowy figure than the other patriarchs, and little if anything can be said of him as a historical figure. He is said to have been born when his parents were both advanced in years as a fulfillment of God's promise to Abraham to grant him posterity against all human expectation (see Rom. 4.16–22). In Genesis 22 God himself seems to challenge his own promise by demanding that Isaac be offered as a human sacrifice, but rewards Abraham's unquestioning obedience by providing a ram as a substitute at the last possible moment. This story (the Aqedah) has been important in Judaism as a reminder of the precariousness of Israel's election and yet the sure promises of God, as well as in Christianity as a “type” of the sacrifice of Christ.
Of Isaac's maturity we learn little. Genesis 24 tells how he acquired a wife (Rebekah), but the principal characters in this tale are Isaac's servant and Rebekah's family. In Genesis 26 Isaac and Rebekah are involved in an incident with “Abimelech king of the Philistines” (an anachronistic reference), who takes Rebekah into his harem—essentially the same incident twice reported of Abraham and Sarah (Gen. 12 and 20). Isaac next appears as an old man, deceived by Jacob into giving him the blessing of the firstborn that should by right have been Esau's (Gen. 27). The stories about Isaac locate him at Beer‐sheba in the far south of Judah (Gen. 26.23–33) and associate him with the worship of the God El‐roi (Gen. 22.14; 24.62), while Jacob later swears by “the Fear of his father Isaac” (Gen. 31.53), perhaps an old divine name (see Names of God in the Hebrew Bible).