Sahih Muslim
Sahih Muslim 1854 d
The obligation to denounce rulers for that in which they go against Shari'ah, but they should not be fought so long as they pray regularly, etc
Arabic hadith text
وَحَدَّثَنَاهُ حَسَنُ بْنُ الرَّبِيعِ الْبَجَلِيُّ، حَدَّثَنَا ابْنُ الْمُبَارَكِ، عَنْ هِشَامٍ، عَنِ الْحَسَنِ، عَنْ ضَبَّةَ بْنِ مِحْصَنٍ، عَنْ أُمِّ سَلَمَةَ، قَالَتْ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم . فَذَكَرَ مِثْلَهُ إِلاَّ قَوْلَهُ " وَلَكِنْ مَنْ رَضِيَ وَتَابَعَ " . لَمْ يَذْكُرْهُ
Translation
Another version omits a portion at the end of the tradition-a portion which begins with man radiya wa taba and ends with the last word of the tradition.