Leviticus 24:19-21

And if a man cause a blemish in his neighbour; as he hath done, so shall it be done to him; breach for breach, eye for eye, tooth for tooth: as he hath caused a blemish in a man, so shall it be done to him again. And he that killeth a beast, he shall restore it: and he that killeth a man, he shall be put to death.