Deuteronomy 22:21-22

21If so, the leaders must take her to the entrance of her father's house. The men of the town must throw stones at her there, until she dies. She has done a very bad thing that brings shame on Israel. She has had sex like a prostitute while she lived in her father's house. You must remove evil acts like this from among you.

22You may discover a man who is having sex with another man's wife. If so, you must punish both the man and the woman with death. In this way, you will remove such evil acts from Israel.