Deuteronomy 19:16-21

161If a malicious witness rises up against a person to testify against him of wrongdoing,

17then both people who have the dispute shall stand 2before the Lord, before the priests and the judges who will be in office in those days.

18And the judges 3shall investigate thoroughly, and if the witness is a false witness and he has testified against his brother falsely,

19then 4you shall do to him just as he had planned to do to his brother. So you shall eliminate the evil from among you.

20And 5the rest of the people will hear and be afraid, and will never again do such an evil thing among you.

21So 67you shall not show pity: 8life for life, 9eye for eye, tooth for tooth, hand for hand, and foot for foot.