What did the Prophet Muhammad (saw) tell Ka`b in response to his troubles caused by the lice?
 Narrated `Abdur-Rahman bin Abu Layla:                     Ka`b bin 'Ujra said that Allah's Apostle said to him (Ka`b), "Perhaps your lice have troubled you?" Ka`b replied, "Yes! O Allah's Apostle." Allah's Apostle said, "Have your head shaved and then either fast three days or feed six poor persons or slaughter one sheep as a sacrifice."