Deuteronomy 19:21

And thine eye shall not pity
The false witness when convicted; this is directed to the judges, who should not spare such an one through favour or affection, but pronounce a righteous sentence on him, and see it executed, in proportion to the crime, and that according to the law of retaliation:

but life shall go for life;
in such a case where the life of a person must have gone, if the falsehood of the testimony had not been discovered, the false witness must suffer death; in other cases, where a member would have been lost, or the price of it paid for, the same penalty was to be inflicted:

eye for eye, tooth for tooth, hand for hand, foot for foot;
that is, the price of an eye an eye see ( Exodus 21:23 Exodus 21:24 ) ( Leviticus 24:19 Leviticus 24:20 ) .