Yahya ibn Yahya narrated to us: Waki' informed us, from Hisham al-Dastawa'i, from Yahya ibn Abi Kathir, from Abdullah ibn Abi Qatadah, from his father, who said: The Messenger of Allah, peace and blessings be upon him, said: "When one of you enters the privy, let him not touch his penis with his right hand."