Numbers 35:2-4

2“Command the sons of Israel that they give to the Levites from the inheritance of their possession cities to live in; and you shall give to the Levites pasture lands around the cities. 3The cities shall be theirs to live in; and their pasture lands shall be for their cattle and for their herds and for all their beasts.

4“The pasture lands of the cities which you shall give to the Levites shall extend from the wall of the city 1outward a thousand cubits around.