Do to him as he meant to do to his brother: this is what is called the lex talionis, the law of equal retaliation. An alternative way of expressing this is “You must punish him in the same way you would have punished the accused person [or, the person he accused of doing wrong].”

Purge the evil from the midst of you: see verse 13; 17.7, 12.

Quoted with permission from Bratcher, Robert G. and Hatton, Howard A. A Handbook on Deuteronomy. (UBS Helps for Translators). New York: UBS, 2000. For this and other handbooks for translators see here .