Numbers 26:54; Numbers 35:8

54 kTo a large tribe you shall give a large inheritance, and to a small tribe you shall give a small inheritance; every tribe shall be given its inheritance in proportion to its list.

And as for the cities that you shall give wfrom the possession of the people of Israel, xfrom the larger tribes you shall take many, and from the smaller tribes you shall take few; each, in proportion to the inheritance that it inherits, shall give of its cities to the Levites.