From the creature of Allah, Ali bin Abi Taalib to Abdullah bin Qays (Abu Musa Ash'ari).
After glorifying Allah and praising the Holy Prophet (s) let it be known to you that I have received reports which may be considered favourable to you, and yet at the same time may be deemed against you (that you on one hand declare me to be a lawful caliph and in the same breath you persuade others not to come to my help). As soon as my messenger reaches you, get ready, come out of your retreat, invite your people to join me and come yourself. If you are convinced that I am on the right side, then you must come to my help and if you feel uncertain, nervous or timid, then get you gone.
I swear by Allah that I shall not let you waver or adopt a double-cross policy. I shall not allow you to sit peacefully at home with a double face, one for each party and I shall expose you to the people. You will find yourself under suspicion from either group and you will be forced to declare your true inclinations.
This revolt which has made Basra as its Headquarters is not an easy joke as you have imagined it to be. It is a great tragedy and it shall have very far-reaching effects. It has to be faced with the calamities which accompany it or which will follow it. It will have to be fought and to get the better of. Therefore, I advise you to think carefully, control your weak and wavering mind and face your lot bravely. And if you are not satisfied with me or have no faith in me then you can with complete freedom go to the other side. You have my unreserved permission. But I am sure you will not be welcomed there.
And if you remain in my camp I shall not allow you to enjoy a restful sleep when Islam itself is in troubles and at war with the rebels. I swear by Allah that this decision of mine is the right step of a faithful Muslim in the right direction.