Sahih al-Bukhari 59:99
Narrated `Aisha:
On the day (of the battle) of Uhud when the pagans were defeated, Satan shouted, "O slaves of Allah! Beware of the forces at your back," and on that the Muslims of the front files fought with the Muslims of the back files (thinking they were pagans). Hudhaifa looked back to see his father "Al-Yaman," (being attacked by the Muslims). He shouted, "O Allah's Slaves! My father! My father!" By Allah, they did not stop till they killed him. Hudhaifa said, "May Allah forgive you." `Urwa said that Hudhaifa continued to do good (invoking Allah to forgive the killer of his father till he met Allah (i.e. died).
Reference
Sahih al-Bukhari 59:99
In-book reference
Book 59, Hadith 99
Arabic Text
حَدَّثَنَا زَكَرِيَّاءُ بْنُ يَحْيَى، حَدَّثَنَا أَبُو أُسَامَةَ، قَالَ هِشَامٌ أَخْبَرَنَا عَنْ أَبِيهِ، عَنْ عَائِشَةَ، رضى الله عنها قَالَتْ لَمَّا كَانَ يَوْمَ أُحُدٍ هُزِمَ الْمُشْرِكُونَ فَصَاحَ إِبْلِيسُ أَىْ عِبَادَ اللَّهِ أُخْرَاكُمْ. فَرَجَعَتْ أُولاَهُمْ فَاجْتَلَدَتْ هِيَ وَأُخْرَاهُمْ، فَنَظَرَ حُذَيْفَةُ فَإِذَا هُوَ بِأَبِيهِ الْيَمَانِ فَقَالَ أَىْ عِبَادَ اللَّهِ أَبِي أَبِي. فَوَاللَّهِ مَا احْتَجَزُوا حَتَّى قَتَلُوهُ، فَقَالَ حُذَيْفَةُ غَفَرَ اللَّهُ لَكُمْ. قَالَ عُرْوَةُ فَمَا زَالَتْ فِي حُذَيْفَةَ مِنْهُ بَقِيَّةُ خَيْرٍ حَتَّى لَحِقَ بِاللَّهِ.