It is narrated from Hazrat Ka'b bin Ujrah (may Allah be pleased with him) that we were in the state of Ihram at Hudaybiyyah with the Noble Prophet (peace and blessings be upon him). The polytheists had surrounded us (and were not allowing us to enter the Haram). My hair had grown very long, and during this time, lice began to fall from my head onto my face. The Noble Prophet (peace and blessings be upon him) passed by me and said, "Are the lice troubling you?" I replied, "Yes!" The Noble Prophet (peace and blessings be upon him) ordered, "Shave your head." On this occasion, this verse was revealed: "And whoever among you is ill or has an ailment of the head (necessitating shaving), he should offer a ransom by fasting, or charity, or sacrifice."