In eulogy of Muhammad, the Umayyads, importance of Imam
Nahj al-Balāgha|Volume 1|Book 1|Chapter 105
فَاللهَ اللهَ أَنْ تَشْكُوا إِلَى مَنْ لاَ يُشْكِي شَجْوَكُمْ، وَلاَ يَنْقُضُ بِرَأْيِهِ مَا قَدْ أَبْرَمَ لَكُمْ. إِنَّهُ لَيسَ عَلَى الاْمَامِ إِلاَّ مَا حُمِّلَ مِنْ أَمْرِ رَبِّهِ: الاْبْلاَغُ فَي الْمَوْعِظَةِ، وَالاجْتِهَادُ فِي النَّصِيحَةِ، وَالاْحْيَاءُ لِلسُّنَّةِ، وَإِقَامَةُ الْحُدُودِ عَلَى مُسْتَحِقِّيهَا، وَإِصْدَارُ السُّهْمَانِ عَلَى أَهْلِهَا. فَبَادِرُوا الْعِلْمَ مِنْ قَبْلِ تَصْوِيحِ نَبْتِهِ، وَمِنْ قَبْلِ أَنْ تُشْغَلُوا بَأَنْفُسِكُمْ عَنْ مُسْتَثَارِ الْعِلْمِ مِنْ عِنْدِ أَهْلِهِ، وَانْهَوْا عَنْ المُنْكَرِ وَتَنَاهَوْا عَنْهُ، فَإِنَّمَا أُمِرْتُمْ بالنَّهْي بَعْدَ التَّنَاهِي!
So fear Allāh and do not place your complaints before him who cannot redress your grievance, nor undo with his opinion what has been made obligatory for you. Certainly, there is no obligation on the Imam except what has been devolved on him from Allāh, namely to convey warnings, to exert in good advice, to revive the Sunnah, to enforce penalties on those liable to them and to issue shares to the deserving. So hasten towards knowledge before its vegetation dries up and before you turn yourselves away from seeking knowledge from those who have it. Desist others from the unlawful and abstain from it yourself, because you have been commanded to abstain (yourself) before abstaining (others).