Sahih al-Bukhari, Volume 9, Book 88, Hadith 177 (USC-MSA) ⓘ

Narrated 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-lslamic period of Ignorance (as rebellious sinners). (Fath-ul-Bari page 112, Vol. 16)

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 ‏" ‏‏.‏