Volume 1 · Book 4 · Hadith 171
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."
— Sahih Bukhari, Volume 1, Book 4: Ablutions (Wudu'), Hadith #171