Numbers 35:16 KJV
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.
Numbers 35:16, King James Version
In context
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.