Numbers 35:15-18 English Standard Version (ESV)

15. These six cities shall be for refuge for the people of Israel, and for the stranger and for the sojourner among them, that anyone who kills any person without intent may flee there.

16. “But if he struck him down with an iron object, so that he died, he is a murderer. The murderer shall be put to death.

17. And if he struck him down with a stone tool that could cause death, and he died, he is a murderer. The murderer shall be put to death.

18. Or if he struck him down with a wooden tool that could cause death, and he died, he is a murderer. The murderer shall be put to death.

Numbers 35