The Prophet ﷺ said during Hajjat-al-Wadaʿ, "Let the people be quiet and listen to me. After me, do not become disbelievers, by striking (cutting) the necks of one another."
قَالَ النَّبِيُّ ﷺ فِي حَجَّةِ الْوَدَاعِ اسْتَنْصِتِ النَّاسَ لاَ تَرْجِعُوا بَعْدِي كُفَّارًا يَضْرِبُ بَعْضُكُمْ رِقَابَ بَعْضٍ رَوَاهُ أَبُو بَكْرَةَ وَابْنُ عَبَّاسٍ عَنِ النَّبِيِّ ﷺ