Numbers 35:6-8

6The cities which you shall give to the Levites shall be the 1six cities of refuge, which you shall provide for the one who commits manslaughter to flee to; and in addition to them you shall give forty-two cities. 7The total number of the cities which you are to give to the Levites shall be 2forty-eight cities, 3together with their pasture lands. 84As for the cities which you shall give them from the possession of the sons of Israel, you shall take more from the larger, and you shall take fewer from the smaller; each shall give some of his cities to the Levites in proportion to his inheritance which he possesses.”