A historical example: the prophet’s grandson, Hussein

About half a century after Muhammad’s death [prayer of God be upon him and his family and peace], his youngest grandson [peace be upon him] is subjected to witness wrongdoing from the government in the name of Islam, while the famous and popular religious elites of the time being silence about it.

The following is a passage which is said to be from him, where he encourages his audience to speak against those wrongs:

اعتبروا أیها الناس بما وعظ الله به أولیاءه من سوء ثنائه علی الأحبار إذ یقول: «لَوْلَا يَنْهَاهُمُ الرَّبَّانِيُّونَ وَالْأَحْبَارُ عَن قَوْلِهِمُ الْإِثْمَ» و قال: «عِنَ الَّذِينَ كَفَرُوا مِن بَنِي إِسْرَائِيلَ عَلَىٰ لِسَانِ دَاوُودَ وَعِيسَى ابْنِ مَرْيَمَ ۚ ذَٰلِكَ بِمَا عَصَوا وَّكَانُوا يَعْتَدُونَ كَانُوا لَا يَتَنَاهَوْنَ عَن مُّنكَرٍ فَعَلُوهُ ۚ لَبِئْسَ مَا كَانُوا يَفْعَلُونَ» و إنما عاب الله ذلك رغبة فیما کانوا ینالون منهم و رهبة مما یحذرون و الله یقول: «فَلَا تَخْشَوُا النَّاسَ وَاخْشَوْنِ» و قال: «وَالْمُؤْمِنُونَ وَالْمُؤْمِنَاتُ بَعْضُهُمْ أَوْلِيَاءُ بَعْضٍ ۚ يَأْمُرُونَ بِالْمَعْرُوفِ وَيَنْهَوْنَ عَنِ الْمُنكَرِ» فبدأ الله بالأمر بالمعروف و النهي عن المنكر فریضة منه، لعلمه بأنها إذا أدیت و أقیمت استقامت الفرائض کلها هینها و صعبها و ذلک أن الأمر بالمعروف و النهي عن المنکر دعاء إلی الإسلام مع رد المظلوم و مخالفة الظالم و قسمة الفيء و الغنائم و أخذ الصدقات من مواضععا في حقها، ثم أنتم أیتها العصابة عصابة بالعلم مشهورة و بالخیر مذکورة و بالنصیحة معروفة و بالله في أنفس الناس مهابة. یهابکم …

الحسن بن علي بن شعبة الحراني (من أعلام القرن الرابع الهجري)، تحف العقول عن آل الرسول

The death of Muawiyah and Hussein’s refusal to accept Muawiyah’s request for the succession of his son, as Muawiyah had already agreed not to seek after as in the treaty with Hussein’s brother [peace be upon them], was the opportunity and the threat for Hussein to find safety … 

Then he started a movement to correct the wrong path that the folk of his grandfather has taken on lately … As one can understand Hussein [peace be upon him] was a brilliant Muslim and a brilliant leader, while his movement was supposedly kept silence by killing him and all the men, and some women and children who followed him on his journey, it is hard to imagine that we would have had the same understanding of Islam, if he hadn’t chosen such path. [peace be upon him]