Qais bin Talq narrates, my father told me this: We were present with the Prophet Muhammad (peace be upon him). A Bedouin came to the Prophet (peace be upon him) and said: O Messenger of Allah! Sometimes one of us is in the state of prayer, he feels an itch, and his hand reaches his private part. The Prophet (peace be upon him) said: That (private part) is a part of your body. The narrator is unsure, perhaps the words are: a lump of flesh from your body.