Siffin, the Arbitration and the Last Days

After 'Uthman's murder, a deep division opened among the Muslims. 'Amr took the side of Mu'awiyah, who demanded justice for 'Uthman's killers, and the two armies met at Siffin in 37 AH. Among those killed on the side of 'Ali was 'Ammar ibn Yasir, of whom the Prophet ﷺ had said that a rebel party would kill him. Sunni scholars treat 'Ali as closer to the truth in this conflict, and honour those on the other side as fellow Companions who made a mistaken judgement or took a different path. They refrain from condemning any of them, as the Qur'an warns against reviling the believers who came before.

When the fighting was stopped by the proposal of arbitration, 'Amr represented Mu'awiyah and Abu Musa al-Ash'ari represented 'Ali. A well-known story says 'Amr tricked Abu Musa into announcing the deposition of both men and then declared Mu'awiyah the caliph. Many scholars, among them Ibn al-'Arabi, rejected this story on the grounds that it comes from Abu Mikhnaf, a narrator whom the hadith critics consider unreliable.

'Amr later governed Egypt again, and died there around 43 AH. On his deathbed he turned his face to the wall and wept, and said that he had once been the Prophet ﷺ's enemy, then his companion, then had been tried by the power of this world. He asked his sons to bury him gently, to stay at his grave for as long as it takes to slaughter a camel and share its meat, so he could take comfort and know how to answer the messengers of his Lord. He placed his hope in Allah's mercy.