John Gill Commentary Genesis 36:7

"For their substance was too great for them to dwell together; and the land of their sojournings could not bear them because of their cattle." — Genesis 36:7 (ASV)

For their riches were more than that they might dwell together ,
&c.] And therefore it was proper to part, as Abraham and Lot had done before, (Genesis 13:6) ; and the land in which they were strangers could not bear them, because
of their cattle ;
their cattle were so numerous that they could not get pasturage for them, there not being enough left them by the inhabitants of it for them to occupy;

nor could they hire land of them sufficient for them both; they being not possessors but sojourners in it, and therefore could have no more of it than the inhabitants thought fit to let to them.