Deuteronomy 17:12

17:12 The person who pays no attention to the priest currently serving the Lord your God there, or to the verdict – that person must die, so that you may purge evil from Israel.

Deuteronomy 22:22

22:22 If a man is caught having sexual relations with a married woman both the man who had relations with the woman and the woman herself must die; in this way you will purge evil from Israel.