Sahih Bukhari Volume 9, Book 92, Hadith 7056

حَدَّثَنَا أَبُو النُّعْمَانِ، حَدَّثَنَا حَمَّادُ بْنُ زَيْدٍ، عَنِ الْجَعْدِ أَبِي عُثْمَانَ، حَدَّثَنِي أَبُو رَجَاءٍ الْعُطَارِدِيُّ، قَالَ سَمِعْتُ ابْنَ عَبَّاسٍ ـ رضى الله عنهما ـ عَنِ النَّبِيِّ صلى الله عليه وسلم قَالَ ‏"‏ مَنْ رَأَى مِنْ أَمِيرِهِ شَيْئًا يَكْرَهُهُ فَلْيَصْبِرْ عَلَيْهِ، فَإِنَّهُ مَنْ فَارَقَ الْجَمَاعَةَ شِبْرًا فَمَاتَ، إِلاَّ مَاتَ مِيتَةً جَاهِلِيَّةً ‏"‏‏

Narrated By Ibn 'Abbas : The Prophet said, "Whoever notices something which he dislikes done by his ruler, then he should be patient, for whoever becomes separate from the company of the Muslims even for a span and then dies, he will die as those who died in the Pre-Islamic period of Ignorance (as rebellious sinners).