Sayyiduna Ka'b bin Ujrah (may Allah be pleased with him) narrates: During Hudaybiyyah, the Prophet Muhammad (peace and blessings be upon him) passed by me while I was lighting a fire under my cooking pot (the narrator is unsure about one word here), and lice were falling on my face. The Prophet (peace and blessings be upon him) asked: O Ka'b! Are the lice troubling you? I replied: Yes, O Messenger of Allah! The Prophet (peace and blessings be upon him) said: Shave your head and offer a sacrifice, or fast for three days, or feed six needy people one sa' (measure) each.