Numbers 35:17

¹⁵  These six cities shall be a refuge, both for the children of Israel, and for the stranger, and for the sojourner among them: that every one that killeth any person unawares may flee thither.

¹⁶  And if he smite him with an instrument of iron, so that he die, he is a murderer: the murderer shall surely be put to death.

¹⁷  And if he smite him with throwing a stone, wherewith he may die, and he die, he is a murderer: the murderer shall surely be put to death.

¹⁸  Or if he smite him with an hand weapon of wood, wherewith he may die, and he die, he is a murderer: the murderer shall surely be put to death.

¹⁹  The revenger of blood himself shall slay the murderer: when he meeteth him, he shall slay him.