Commentary for Genesis 36:9

ואלה AND THESE — are the generations that his sons begat after he went to Seir.

AND THESE ARE THE GENERATIONS OF ESAU THE FATHER OF EDOM. Scripture comes to mention the generations which his children begot after they went with him to Se’ir for Esau did not beget there. Thus Scripture begins from him by saying that he had already begotten Eliphaz and Re’uel,²⁵⁹Verse 10 here. and they begot these children in the land of Se’ir. It also mentions together with them the children of Oholibamah,²⁶⁰Verse 14 here. who were born in the land of Canaan,²⁶¹Verse 5 here. even though it does not mention any children that were born to them in the land of Se’ir,²⁶²According to Ramban above, the justification for mentioning the birth of Eliphaz and Re’uel was in order to mention their offspring. Why then was the birth of Oholibamah’s children mentioned? The answer is: “in order that they, etc.” so that they be counted together with their brothers, the sons of Esau, mentioned in the beginning of the section. It is also mentioned because they became chieftains in Se’ir since Scripture mentions all their chieftains.

ואלה תולדות עשו, a reference to his grandchildren, similar to Genesis 10,1 where after the same introduction, the grandsons of Noach are listed by the Torah. [not quite, as the chapter starts with the words ואלה תולדות בני נח. Ed.]

ואלה תולדות, now the Torah lists the descendants that were born to him while he lived in Mount Seir.

ואלה תולדות עשו, and the following are Esau’s developments.” The Torah proceeds to list biological descendants of Esau born after his migration to Seir, for he himself is not reported to have sired any more children at that time. Still, the Torah relates the descendants by starting with Esau having sired Eliphaz, etc. The children of Oholivamah who had been born in the land of Canaan are also mentioned here once more. By doing so, the Torah made sure they were included in the count with their brothers.