Numbers 35:12-19

121The cities shall be to you as a refuge from the avenger, so that the manslayer will not die until he stands before the congregation for 2trial. 13The cities which you are to give shall be your six cities of refuge. 14You 3shall give three cities across the Jordan and three cities 4in the land of Canaan; they are to be cities of refuge. 15These six cities shall be for refuge for the sons of Israel, and for the alien and for the sojourner among them; that anyone who 5kills a person 6unintentionally may flee there.

16‘7But if he struck him down with an iron object, so that he died, he is a murderer; the murderer shall surely be put to death. 17If he struck him down with a stone in the hand, by which he will die, and as a result he died, he is a murderer; the murderer 8shall surely be put to death. 18Or if he struck him with a wooden object in the hand, by which he might die, and as a result he died, he is a murderer; the murderer shall surely be put to death. 19The blood avenger himself shall put the murderer to death; he shall put him to death when he meets him.