Numbers 35:6-16

6 The cities you give to the L'vi'im are to be the six cities of refuge to which you permit the person who kills someone to flee to; plus an additional forty-two cities.
7 Thus you will give the L'vi'im forty-eight cities, with their surrounding open land.
8 As to the cities you will give from those the people of Isra'el possess, from the many you will take many, and from the few you will take few - each tribe will contribute from its cities to the L'vi'im in accordance with the size of its inheritance."
9 ADONAI said to Moshe,
10 "Tell the people of Isra'el, 'When you cross the Yarden into the land of Kena'an,
11 you are to designate for yourselves cities that will be cities of refuge for you, to which anyone who kills someone by mistake can flee.
12 These cities are to be a refuge for you from the dead person's next-of-kin, who might otherwise avenge his kinsman's death by slaying the killer prior to his standing trial before the community.
13 In regard to the cities you are to give, there are to be six cities of refuge for you.
14 You are to give three cities east of the Yarden and three cities in the land of Kena'an; they will be cities of refuge.
15 These six cities will serve as refuge for the people of Isra'el, as well as for the foreigner and resident alien with them; so that anyone who kills someone by mistake may flee there.
16 "'However, if he hits him with an iron implement and thus causes his death, he is a murderer; the murderer must be put to death.
Complete Jewish Bible Copyright 1998 by David H. Stern. Published by Jewish New Testament Publications, Inc. All rights reserved. Used by permission.