בראשית, פרק ל״ו, פסוק ז׳

The physical separation between Jacob and Esau was driven first and foremost by their immense economic success. Because both brothers were shepherds who had gathered massive flocks, a practical reality forced them to move away from one another [ביאור שטיינזלץ]. The surrounding area simply could not provide enough pasture to sustain the vast number of animals they owned [רש"י, ביאור ישר].

This raises a practical question about the geography of the region: was the entire land of Canaan truly not large enough to hold them both? To explain this, commentators point out that their dwelling area refers specifically to their home city of Hebron, where Abraham and Isaac had lived, rather than the entire land. The land of Canaan could have supported a thousand times their wealth. However, once Esau realized he could not continue living alongside his brother in the confined space of their city, he decided to leave the region entirely, leaving it in Jacob's hands [רמב״ן, הטור הארוך, ביאור ישר].

Beyond the practical lack of grazing space, there were deeper, more personal motives behind Esau's departure. A primary approach among commentators suggests that Esau chose to distance himself from Jacob to escape a decree from God placed upon Isaac's descendants, which stated they would be strangers in a foreign land. Esau preferred to completely give up his share in the gift of the land just so he would not have to pay the heavy price of exile and slavery. Coupled with this desire to escape the decree was a deep sense of shame. Esau felt profoundly embarrassed about selling his birthright to Jacob, and this shame ultimately pushed him to distance himself from his brother permanently [רש"י, מזרחי, שפתי חכמים].