Cross reference
Exodus 21:23
23 But if any harm follows, then you must take life for life,
Deuteronomy 19:21
21 Your eyes shall not pity; life [shall go] for life, eye for eye, tooth for tooth, hand for hand, foot for foot.
Leviticus 24:19
19 If anyone injures his neighbor; as he has done, so shall it be done to him:
Numbers 35:31
31 Moreover you shall take no ransom for the life of a murderer who is guilty of death; but he shall surely be put to death.