you are to cut off her hand. You must show her no pity.

Deuteronomy 7:2
and when the LORD your God has delivered them over to you to defeat them, then you must devote them to complete destruction. Make no treaty with them and show them no mercy.

Deuteronomy 19:13
You must show him no pity. You are to purge from Israel the guilt of shedding innocent blood, that it may go well with you.

Deuteronomy 25:11
If two men are fighting, and the wife of one steps in to rescue her husband from the one striking him, and she reaches out her hand and grabs his genitals,

Then you shall cut off her hand, your eye shall not pity her.