A commander (of the Muslims) is a shield for them. They fight behind him and they are protected by (him from tyrants and aggressors). If he enjoins fear of God, the Exalted and Glorious, and dispenses justice, there will be a (great) reward for him; and if he enjoins otherwise, it redounds on him. (Using translation from Muslim 1841)  

عَنْ رَسُولِ اللهِ ﷺ قَالَ وَقَالَ «إِنَّمَا الْإِمَامُ جُنَّةٌ يُقَاتَلُ مِنْ وَرَائِهِ وَيُتَّقَى بِهِ فَإِنْ أَمَرَ بِتَقْوَى اللهِ وَعَدَلَ كَانَ لَهُ بِذَلِكَ أَجْرًا وَإِنْ يَأْمُرْ بِغَيْرِهِ فَإِنَّ عَلَيْهِ مِنْهُ»