Numbers 35:2-8

2Command the children of Israel, that they give to the Levites of the inheritance of their possession cities to dwell in; and ye shall give also to the Levites common lands for the cities around them. 3And they shall have the cities to dwell in; and the common lands of them shall be for their cattle, and for their goods, and for all their beasts. 4And the common lands of the cities, which ye shall give to the Levites, shall reach from the wall of the city and outward a thousand cubits on all sides. 5And ye shall measure from outside the city on the east side two thousand cubits, and on the south side two thousand cubits, and on the west side two thousand cubits, and on the north side two thousand cubits; and the city shall be in the midst: this shall be to them the common lands of the cities. 6And among the cities which ye shall give to the Levites there shall be six cities for refuge, which ye shall appoint for the manslayer, that he may flee there: and to them ye shall add forty and two cities.1 7So all the cities which ye shall give to the Levites shall be forty and eight cities: them shall ye give with their common lands. 8And 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 to the Levites according to his inheritance which he inheriteth.2