Be wary of mere opinion. I saw myself on the day of Abu Jandal, and had I been able to reject the command of the Messenger of Allah ﷺ, I would have rejected it. But Allah and His Messenger know best. We have never placed our swords upon our shoulders facing some matter that alarmed us except that they led us smoothly to an outcome we recognized, until this present matter. We close no breach in it except that another breach bursts open upon us, and we do not know how to deal with it.
اتهموا الرأي، فلقد رأيتني يوم أبي جندل ولو أستطيع أن أرد على رسول الله ﷺ أمره لرددت، والله ورسوله أعلم، وما وضعنا أسيافنا على عوانقنا لأمر يفظعنا إلا أسهلن بنا إلى أمر نعرفه قبل هذا الأمر، ما نسد منها خصما إلا انفجر علينا خصم ما ندري كيف نأتي له.
Bukhari narrated it in Maghazi (4189), and Muslim in Jihad and Sair (96:1785), both through Malik bin Mughul, who said, "I heard Abu Husayn say that Abu Waail said, 'When Sahl bin Hunayf came from Siffin, we went to him seeking news, and he said,'" then he mentioned it.