This is the account of Esau (that is, Edom).
1. Now these are the generations of Esau. Though Esau was an alien from the Church in the sight of God; yet since he also, as a son of Isaac, was favored with a temporal blessing, Moses celebrates his race, and inscribes a sufficiently lengthened catalogue of the people born from him. This commemoration, however, resembles an honorable sepulture.
Observe here, 1. Concerning Esau himself, Gen 36:1. He is called Edom (and again, Gen 36:8), that name by which was perpetuated the remembrance of the foolish bargain he made, when he sold his birthright for that red, that red pottage. The very mention of that name is enough to intimate the reason why his family is turned off with such a short account.
Commenting on Genesis 36:1-8
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, Gen 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...