Sahih Bukhari Volume 005, Book 058, Hadith Number 161.
Hadith Section/Book: Sahih Bukhari Sahih Bukhari Book 58. Merits of the Helpers in Madina (Ansaar)
Narated By 'Aisha : On the day of the battle of Uhud the pagans were defeated completely. Then Satan shouted loudly, "O Allah's slaves! Beware the ones behind you!" So the front files attacked the back ones. Then Hudhaifa looked and saw his father, and said loudly, "O Allah's slaves! My father! My father!" By Allah, they did not stop till they killed him (i.e. Hudaifa's father). Hudhaifa said, "May Allah forgive you!" The sub-narrator said, "By Allah, because of what Hudhaifa said, he remained in a good state till he met Allah (i.e. died)."