To Abu Musa al-Ash`ari in reply to his letter regarding the two arbitrators. Sa`id ibn Yahya al-Umawi has mentioned this in his "Kitab al-maghazi"
Certainly, many people have turned away from many a (lasting) benefit (of the next life), for they bent towards the world and spoke with passions. I have been struck with wonder in this matter, upon which people who are self-conceited have agreed. I am providing a cure for their wound but I fear lest it develops into a clot of blood (and becomes incurable). Remember that no person is more covetous than I for the unity of the ummah of Muhammad (may Allah bless him and his descendants) and their solidarity. I seek through it good reward and an honourable place to return to.
I shall fulfil what I have pledged upon myself even though you may go back from the sound position that existed when you left me last, because wretched is he who is denied the benefit of wisdom and experience. I feel enraged if anyone speaks wrong, or if I should worsen a matter which Allah has kept sound. Therefore, leave out what you do not understand, because wicked people will be conveying to you vicious things; and that is an end to the matter.