(15) بَابُ إِذَا حَنِثَ نَاسِيًا فِي الأَيْمَانِ
Narrated `Aisha:
When the pagans were defeated during the (first stage) of the battle of Uhud, Satan shouted, "O Allah's slaves! Beware of what is behind you!" So the front files of the Muslims attacked their own back files. Hudhaifa bin Al-Yaman looked and on seeing his father he shouted: "My father! My father!" By Allah! The people did not stop till they killed his father. Hudhaifa then said, "May Allah forgive you." `Urwa (the sub-narrator) added, "Hudhaifa continued asking Allah forgiveness for the killers of his father till he met Allah (till he died).
Reference: Sahih al-Bukhari 6668
In-book reference: Book 83, Hadith 46
USC-MSA web (English) reference(deprecated numbering scheme): Vol. 8, Book 78, Hadith 661