The Lord wanted Israel to inherit the Land of Canaan, but He wanted it divided up, giving each tribe a piece of land. Joshua and Eleazar would head up the process, but the Lord also wanted leaders from all the tribes involved,

“And you shall take one leader of every tribe to divide the land for the inheritance…These are the ones the Lord commanded to divide the inheritance among the children of Israel in the land of Canaan” (Numbers 34:18–29).

The Lord could have done it all Himself, but He wants His people involved, even as now He could do everything for us, but He does not operate that way, for what we are able to do, He expects us to do, and what we cannot do, He will do for us.