בראשית, פרק ל״ו, פסוק ט׳

The physical relocation of Esau's family away from the land of Canaan represents a major turning point, marking their shift from a small nuclear family into a large, established nation. Having previously established the direct sons born before the move, the historical account now shifts to the expansion of his dynasty beyond the borders of his original homeland [פענח רזא].

The primary approach among commentators is that the subsequent family lineage details Esau's grandchildren rather than his immediate children. He did not father any additional children after leaving Canaan. Instead, he serves merely as the ancestral starting point for his sons, who went on to build the listed family lines [רשב״ם, רמב״ן, גור אריה]. The emphasis on Mount Seir clarifies that these grandchildren were born after the family had successfully migrated and put down roots in the region [רש״י, רד״ק, מזרחי]. There is an exception within this record, as the sons of Oholibamah were actually born back in Canaan. They are grouped here to keep the brothers united in the narrative, and because they too eventually rose to become tribal leaders in the new territory [רמב״ן, הטור הארוך].

This geographic shift profoundly altered Esau's national standing. While he lived in Canaan, he alone bore the title of Edom, and his family had not yet formed a distinct people. It was only after they settled in Mount Seir that his descendants united into an independent nation. Through this settlement, Esau officially transformed into the founding father of the Edomite nation [העמק דבר].