Numbers 35:2-8

2Command the children of Israel, that of the inheritance of their possession they give unto the Levites cities to dwell in; and a suburb for the cities round about them shall ye give unto the Levites.

3And the cities shall they have to dwell in, and their suburbs shall be for their cattle, and for their goods, and for all their beasts.

4And the suburbs of the cities that ye shall give unto the Levites shall be from the walls of the city outward, a thousand cubits round about.

5And ye shall measure, without the city, the east side two thousand cubits, and the south side two thousand cubits, and the west side two thousand cubits, and the north side two thousand cubits, and the city shall be in the midst: they shall have this as suburbs of the cities.

6And [among] the cities that ye shall give unto the Levites [shall be] the six cities of refuge, which ye shall appoint for the manslayer, that he may flee thither, — and besides them ye shall give forty-two cities:

7all the cities that ye shall give to the Levites shall be forty-eight cities, they and their suburbs.

8And the cities which ye shall give shall be of the possession of the children of Israel: from them that have much ye shall take much, and from them that have little ye shall take little; each one according to his inheritance which he will inherit shall give of his cities to the Levites.