Full Sharh — Mishkat al-Masabih 3515
وَعَنْ أُمِّ سَلَمَةَ قَالَتْ: قَالَ رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ: «يَكُونُ عَلَيْكُمْ أُمَرَاءُ تَعْرِفُونَ وَتُنْكِرُونَ فَمَنْ أَنْكَرَ فَقْدَ بَرِئَ وَمَنْ كَرِهَ فَقَدْ سَلِمَ وَلَكِنْ مَنْ رَضِيَ وَتَابَعَ» قَالُوا: أَفَلَا نُقَاتِلُهُمْ؟ قَالَ: «لَا مَا صَلَّوْا لَا مَا صَلَّوْا» أَيْ: مَنْ كَرِهَ بِقَلْبِهِ وَأنكر بِقَلْبِه. رَوَاهُ مُسلم
English Translation
Umm Salama reported God’s Messenger as saying, “You will have commanders some of whom you will approve and some of whom you will disapprove. He who expresses disapproval is guiltless and he who feels disapproval is safe, but he who is pleased and follows them ...” His hearers interrupted, “Shall we not fight with them?” but he replied, “No, as long as they pray; no, as long as they pray.” It means one who feels disapproval in his heart and expresses disapproval in his heart. Muslim transmitted it.
Source
Mishkat al-Masabih(مشكاة المصابيح)
The Offices of Commander and Qadi
Hadith Number
3515