I have appointed Malik bin Harith as chief of the staff over you and the armies under you. Take your orders from him and obey him. Treat him as if he is your shield and armour because there is no risk of laziness or lethargy from him, nor of nervousness and blunders nor of any error of commission and omission.
When Imam Ali (a) sent an expedition of 3000 soldiers under Ma'qil bin Qays Riyahi against the Syrians, he issued the following instructions.
At Siffin Imam Ali (a) gave the following instructions to his soldiers before the battle.