This chapter gives us a genealogical account of Esau's family, of his wives and sons, with whom he removed from Seir, Ge 36:1; of his sons' sons, or grandsons, who were dukes in the land of Edom, Ge 36:11; after which is inserted a genealogy of Seir the Horite, into whose family Esau married, and of his children, and the dukes among them, Ge 36:20; then follows a list of the kings of Edom, before there were any in Israel, Ge 36:31; and the chapter is closed with a brief narration of the dukes of Esau, according to their families, Ge 36:40.
Ver. 1. Now these [are] the generations of Esau, who [is] Edom. Who was surnamed Edom, from the red pottage he sold his birthright for to his brother Jacob, Ge 25:30; an account is given of him, and his posterity, not only because he was a son of Isaac, lately made mention of as concerned in his burial; but because his posterity would be often taken notice of in the sacred Scriptures, and so their genealogy would serve to illustrate such passages; and Maimonides thinks the principal reason is, that whereas Amalek, a branch of Esau's family, were to be destroyed by an express command of God, it was necessary that all the rest should be particularly described, lest they should all perish together; but other ends are answered hereby, as partly to show the fulfilment of the promise to Abraham, concerning the multiplication of his seed, and the accomplishment of the oracle to Rebekah, signifying that two nations were in her womb, one of which were those Edomites; as also to observe how the blessing of Isaac his father came upon him with effect, Ge 22:17.
Moreh Nevochim, par. 3. c. 50. p.