From Sahih Bukhari (Hadith 170):
Narrated Ibn Seereen:I said to `Abida, "I have some of the hair of the Prophet (ﷺ) 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
Reference: Bukhari 170