TSK · Deuteronomy 22:30

"'The man who lies with his father's wife has uncovered his father's nakedness: both of them shall surely be put to death; their blood shall be upon them.

He said, "Who are you?" She answered, "I am Ruth your handmaid. Therefore spread your skirt over your handmaid; for you are a near kinsman."

It is actually reported that there is sexual immorality among you, and such sexual immorality as is not even named among the Gentiles, that one has his father's wife.