The older son of Isaac and Rebekah, and the twin brother of Jacob (Gen. 25.24–26). His ruddy and hairy appearance, as well as his preference for hunting and the outdoor life, distinguished him from his brother. Despite the apparent connection between his name and his hairiness in Genesis 25.25, the etymology of Esau remains uncertain. Esau also is considered the ancestor of the Edomites (Gen. 36.9).

Genesis 25.29–34 relates how Esau foolishly sold his birthright to Jacob for the price of a meal whose name in Hebrew (ʾādōm) resembles Edom, another name for Esau (Gen. 36.1). Jacob, acting on the advice of Rebekah, then tricked Isaac into making him the principal heir by disguising himself as his older brother and obtaining his father's blessing (Gen. 27). Esau eventually shunned revenge, was reconciled with Jacob, and settled in Seir (Gen. 33).

Most scholars view the stories of Jacob and Esau not only as folktales about fraternal relationships and reversals of fortune but also as Israelite depictions of the ambivalent and sometimes treacherous relationship between Edomites (sons of Esau) and Israelites (sons of Jacob) over territorial claims and other ethnopolitical issues (2 Sam. 8.12–14; 2 Kings 8.20–22; Obad.). Ethnopolitical relationships are ostensibly reflected in notices about Esau's marriages to women of various ethnic origins (Gen. 26.34; 28.9) and about his progeny (Gen. 36).

Within Christianity Esau became a central example in debates concerning the right of Christians to the blessings promised by God to the descendants of Isaac (Rom. 9.6–14) and in debates about predestination.

Hector Ignacio Avalos