Sahih al-Bukhari 7111
Narrated Nafi`:
When the people of Medina dethroned Yazid bin Muawiya, Ibn `Umar gathered his special friends 
and children and said, "I heard the Prophet (ﷺ) saying, 'A flag will be fixed for every betrayer on the Day 
of Resurrection,' and we have given the oath of allegiance to this person (Yazid) in accordance with 
the conditions enjoined by Allah and His Apostle and I do not know of anything more faithless than 
fighting a person who has been given the oath of allegiance in accordance with the conditions 
enjoined by Allah and His Apostle , and if ever I learn that any person among you has agreed to 
dethrone Yazid, by giving the oath of allegiance (to somebody else) then there will be separation 
between him and me."
حَدَّثَنَا سُلَيْمَانُ بْنُ حَرْبٍ، حَدَّثَنَا حَمَّادُ بْنُ زَيْدٍ، عَنْ أَيُّوبَ، عَنْ نَافِعٍ، قَالَ لَمَّا خَلَعَ أَهْلُ الْمَدِينَةِ يَزِيدَ بْنَ مُعَاوِيَةَ جَمَعَ ابْنُ عُمَرَ حَشَمَهُ وَوَلَدَهُ فَقَالَ إِنِّي سَمِعْتُ النَّبِيَّ صلى الله عليه وسلم يَقُولُ ‏
"‏ يُنْصَبُ لِكُلِّ غَادِرٍ لِوَاءٌ يَوْمَ الْقِيَامَةِ ‏"‏‏.‏ وَإِنَّا قَدْ بَايَعْنَا هَذَا الرَّجُلَ عَلَى بَيْعِ اللَّهِ وَرَسُولِهِ، وَإِنِّي لاَ أَعْلَمُ غَدْرًا أَعْظَمَ مِنْ أَنْ يُبَايَعَ رَجُلٌ عَلَى بَيْعِ اللَّهِ وَرَسُولِهِ، ثُمَّ يُنْصَبُ لَهُ الْقِتَالُ، وَإِنِّي لاَ أَعْلَمُ أَحَدًا مِنْكُمْ خَلَعَهُ، وَلاَ بَايَعَ فِي هَذَا الأَمْرِ، إِلاَّ كَانَتِ الْفَيْصَلَ بَيْنِي وَبَيْنَهُ‏.‏