Why does the Pasuk list the generations of Esav twice?
Rashi, Moshav Zekenim, Ramban and Seforno: The first time, it lists his generations that he himself bore while he still lived in Eretz Kena'an; the second time, it lists those that his children bore after he moved to Har Se'ir. 1
Where it was not he, but his children, who bore children, who subsequently became chieftains there (Ramban, Seforno and Rashbam). And it adds the sons of Aholivamah, who did not bear children in Har Se'ir, in order to include them together with the other sons of Esav and because they too, became chiefs (Ramban).
Why does it say "Avi Edom b'Har Se'ir"?
Ha'amek Davar: As long as he was in Eretz Yisrael, he did not merit that his sons be called a nation by themselves, the nation of Edom; only Esav himself was called Edom. After he went to Se'ir, his sons were called the nation of Edom, and he was the father of Edom.
QUESTIONS ON RASHI
Rashi writes: "These are the offspring that Esav's children now had, after he went to Se'ir." Why must we interpret this way?
Gur Aryeh: No new sons of Esav are recorded in the ensuing verses (36:10-14), only grandsons.
