Numbers 35:6; Numbers 35:11-14

6 "The cities that you give to the Levites shall be the six cities of refuge, where you shall permit the manslayer to flee, and in addition to them you shall give forty-two cities.

11 then you shall select cities to be cities of refuge for you, that the manslayer who kills any person without intent may flee there.

12 The cities shall be for you a refuge from the avenger, that the manslayer may not die until he stands before the congregation for judgment.

13 And the cities that you give shall be your six cities of refuge.

14 You shall give three cities beyond the Jordan, and three cities in the land of Canaan, to be cities of refuge.