Musannaf Ibn Abi Shayba 9:1695

Ahmad ibn Abd Allah narrated to us, from Ibn Shihab, from Ibn Abi Layla, from Abu al-Zubayr, from Jabir, who said: The Messenger of Allah (may Allah bless him and grant him peace) forbade that a man should have skin-to-skin contact with a man, and a woman with a woman. Ibn Abi Layla said: And I am of the opinion that there is a discretionary punishment (*ta'zir*) for that.