Numbers 35:6

4“The pasture lands of the cities, which you shall give to the Levites, shall be from the wall of the city and outward one thousand cubits around it.

5You shall measure outside of the city for the east side two thousand cubits, and for the south side two thousand cubits, and for the west side two thousand cubits, and for the north side two thousand cubits, the city being in the middle. This shall be the pasture lands of their cities.

6“The cities which you shall give to the Levites, they shall be the six cities of refuge, which you shall give for the man slayer to flee to. Besides them you shall give forty-two cities.

7All the cities which you shall give to the Levites shall be forty-eight cities together with their pasture lands.

8Concerning the cities which you shall give of the possession of the children of Israel, from the many you shall take many, and from the few you shall take few. Everyone according to his inheritance which he inherits shall give some of his cities to the Levites.”