A letter sent by Imam Ali (A.S.) to the people of various provinces, giving them the causes of the Battle of Siffin.
The thing began in this way: We and the Syrians were facing each other while we had common faith in one Allah, in the same Prophet (peace be upon him and his household) and on the same principles and canons of religion. So far as faith in Allah and the Holy Prophet (peace be upon him and his household) was concerned we never wanted them (the Syrians) to believe in anything over and above or other than what they were believing in and they did not want us to change our faith. Both of us were united on these principles. The point of contention between us was the question of the murder of Uthman. It had created the split. They wanted to lay the murder at my door while I am actually innocent of it.
I advised them that this problem cannot be solved by excitement. Let the excitement subside, let us cool down; let us do away with sedition and revolt; let the country settle down into a peaceful atmosphere and when once a stable regime is formed and the right authority is accepted, then let this question be dealt with on the principles of equity and justice because only then the authority will have power enough to find the criminals and to bring them to justice. They refused to accept my advice and said that they wanted to decide the issue on the point of the sword.
When they thus rejected my proposal of peace and kept on sabre rattling threats, then naturally the battle, which was furious and bloody, started. When they saw defeat facing them across the battlefield, when many of them were killed, and many more wounded, then they went down on their knees and proposed the same thing, which I had proposed before the bloodshed had begun.
I accepted their proposal so that their desire might be fulfilled, my intentions of accepting the principles of truth and justice and acting according to these principles might become clear and they might have no cause to complain against me.
Now whoever adheres firmly to the promises made will be the one whose salvation will be saved by Allah and one who will try to go back upon the promises made, will fall deeper and deeper into heresy, error and loss. His eyes will be closed to realities and truth in this world and he will be punished in the next world.