Abu Sa’id al-Khudri reported: The Messenger of Allah, peace and blessings be upon him, said, “Every treacherous person will have a banner raised over him on the Day of Resurrection according to the measure of his betrayal. Surely, there is no greater betrayal than that committed by a ruler over the commoners.”
Source: Ṣaḥīḥ Muslim 1738
Grade: Sahih (authentic) according to Muslim
عَنْ أَبِي سَعِيدٍ الْخُدْرِيِّ قَالَ قَالَ رَسُولُ اللهِ صَلَّى اللهُ عَلَيْهِ وَسَلَّمَ لِكُلِّ غَادِرٍ لِوَاءٌ يَوْمَ الْقِيَامَةِ يُرْفَعُ لَهُ بِقَدْرِ غَدْرِهِ أَلَا وَلَا غَادِرَ أَعْظَمُ غَدْرًا مِنْ أَمِيرِ عَامَّةٍ
1738 صحيح مسلم كتاب الجهاد والسير باب تحريم الغدر