Ablutions (Wudu')
Bukhari :: Book 1 :: Volume 4 :: Hadith 171
Narrated Ibn Sirrn:
I said to 'Ablda, "I have some of the hair of the Prophet which I got from Anas or from his family." 'Abida replied. "No doubt if I had a single hair of that it would have been dearer to me than the whole world and whatever is in it."