Numbers 35:8

And the cities which ye shall give shall be of the possession of the children of Israel: from them that have many ye shall give many; but from them that have few ye shall give few: every one shall give of his cities unto the Levites according to his inheritance which he inheriteth.

The cities ... shall be of the possession ... of Israel. The burden of furnishing those places for the residence and support of the Levitical order was to fall in equitable proportions upon the different tribes (see Numbers 33:54; Joshua 20:7). The larger and wealthier tribes were to support a greater number than the smaller and poorer ones; but the distribution of the whole Levitical body was accommodated to the number of the tribes.