Sahih Muslim 2908 a
Abu Huraira reported Allah's Messenger (ﷺ) as saying:
By Him in Whose Hand is my life, a time would come when the murderer would not know why he has committed the murder, and the victim would not know why he has been killed.
وَحَدَّثَنَا ابْنُ أَبِي عُمَرَ الْمَكِّيُّ، حَدَّثَنَا مَرْوَانُ، عَنْ يَزِيدَ، - وَهُوَ ابْنُ كَيْسَانَ - عَنْ 
 أَبِي حَازِمٍ، عَنْ أَبِي هُرَيْرَةَ، قَالَ قَالَ النَّبِيُّ صلى الله عليه وسلم ‏
"‏ وَالَّذِي نَفْسِي بِيَدِهِ لَيَأْتِيَنَّ
 عَلَى النَّاسِ زَمَانٌ لاَ يَدْرِي الْقَاتِلُ فِي أَىِّ شَىْءٍ قَتَلَ وَلاَ يَدْرِي الْمَقْتُولُ عَلَى أَىِّ شَىْءٍ قُتِلَ
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