Numbers 35:16-21

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. 17And 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. 18Or 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. 19The avenger of blood shall himself put the murderer to death; when he meets him, he shall put him to death. 20And if he pushed him out of hatred or hurled something at him, lying in wait, so that he died, 21or in enmity struck him down with his hand, so that he died, then he who struck the blow shall be put to death. He is a murderer. The avenger of blood shall put the murderer to death when he meets him.