Ibn ‘Abbas reported the Prophet as saying, “When a man calls another a Jew give him twenty lashes, when he calls someone a mukhannath* give him twenty lashes, and kill anyone who has intercourse with a woman who is within the prohibited degress.”
Tirmidhi transmitted it, saying this is a gharib tradition.
* Mukhannaths were sexually abnormal men who imitated women. Some of them were signets.