Hadith 1390
۞
Therefore, listen to him and obey his orders that accord with right, because he is a sword among the swords of Allāh, whose edge is not dull and which does not miss its victim. If he orders you to advance, advance, and if he orders you to stay, stay, because he surely neither advances or attacks nor puts anyone backward or forward save with my command. I have preferred him for you rather than for myself because of his being your well-wisher and (because of) the severity of his harshness over your enemies.
فَاسْمَعُوا لَهُ وَأَطِيعُوا أَمْرَهُ فِيمَا طَابَقَ الْحَقَّ، فَإِنَّهُ سَيْفٌ مِنْ سُيُوفِ اللهِ، لَا كَلِيلُ الظُّبَةِ، وَلَا نَابِي الضَّرِيبَةِ، فَإِنْ أَمَرَكُمْ أَنْ تَنْفِرُوا فانْفِرُوا، وَإِنْ أَمَرَكُمْ أَنْ تُقيِمُوا فَأَقِيمُوا، فَإِنَّهُ لَا يُقْدِمُ وَلَا يُحْجِمُ، وَلَا يُؤَخِّرُ وَلَا يُقَدِّمُ إِلَّا عَنْ أَمْرِي، وَقَدْ آثَرْتُكُمْ بِهِ عَلَى نَفْسِي لِنَصِيحَتِهِ لَكُمْ، وَشِدَّةِ شَكِيمَتِهِ عَلَى عَدُوِّكُمْ.