What did the Prophet Muhammad (saw) say to Ka`b bin 'Ujara after noticing lice in his hair?
 Narrated Ka`b bin 'Ujara:                     The Prophet passed by me while I was kindling a fire under a (cooking) pot. He said, "Do the lice of your head trouble you?" I said, "Yes." So he called a barber to shave my head and ordered me to make expiation for that."