To Ahu Musa al-Ash`ari, Governor of Kufa when Imam learnt he was dissuadingpeople of Kufa from joining battle of Jamal when Imam had called them to fight along with him.
From the servant of Allah, Ameerul Momineen to Abdullah ibn Qays:
Now, I have come to know of words uttered by you which go in your favour as well as against you. So, when my messenger reaches you prepare yourself and get ready, come out of your den and call those who are with you. Then, if you are convinced of the truth get up but if you feel cowardice go away. By Allah, you will be caught wherever you may be and you will not be spared till you are completely upset and everything about you is scattered and till you are shaken from your seat. Then, you will fear from your front as you do from the rear.
What you hope is not a light matter, but it is serious calamity.We have to ride its camels, overcome its difficulties and level its mountains. Set your mind in order, take a grip on your affairs and acquire your share. If you do not like it then go away to where neither you are welcome nor can you escape from it. It is better that you be left alone and lie sleeping. Then no one will enquire where is so-and-so. By Allah, this is the case of right with the rightful person and we do not care what the heretics do.