Sahih Bukhari
Sahih Bukhari Volume 007, Book 072, Hadith Number 716.
Hadith Section/Book: Sahih Bukhari Sahih Bukhari Book 72. Dress
Narrated By Sad : On the day of the battle of Uhud, on the right and on the left of the Prophet were two men wearing white clothes, and I had neither seen them before, nor did I see them afterwards.