If two factions of believers fight...

If two factions of believers fight, make peace between them, but if one of them rebels against the other, fight the one which is rebellious until it returns to God's command. (49:9) The statement, made by the Noble Messenger concerning 'Ammar, gave him great prestige. Accordingly, during the Battle of Siffin, when 'Ammar fought on the side of Imam 'Ali ('a), Ammar's presence in 'Ali's troops was considered a strong point in 'Ali's favour.

There were people with a weak faith who, until 'Ammar had not been killed, were not convinced that it was right for them to fight on Ali's side and lawful to kill Mu'awiyah and his soldiers. But on the day that 'Ammar was killed at the hands of Mu'awiyah's soldiers, suddenly a cry rose from all sides that the Prophet's prophesy had come true.

The best evidence of the unrighteousness of Mu'awiyah and his companions was that they were the killers of 'Ammar and the Prophet had informed years ago through his statement that 'Ammar will be killed by a rebellious faction.2 On this day it became quite clear that the Mu'awiyah's troops represented the rebellious faction, that is, one which was unjust and unrighteous, and that justice lay on the side of 'Ali's army.

Hence in accordance with the express injunction of the Qur'an one had to join the battle on 'Ali's side and against Mu'awiyah's army. This incident demoralized Mu'awiyah's troops. Mu'awiyah, who always tried to make a headway by resorting to cunning and subterfuge, resorted to a misinterpretation.

It was not possible to deny that the Prophet had made such a statement concerning 'Ammar, because perhaps there were at least five hundred persons who could bear witness that they had heard this statement from the Prophet himself or from someone who had heard it from the Prophet. Accordingly, it was not possible to deny the fact of the prophesy concerning 'Ammar.

The Syrians protested to Mu'awiyah, for it were they who had killed 'Ammar and the Prophet had said that he would be killed by a rebellious faction. Mu'awiyah told them, "You are mistaken. It is true that the Prophet said 'Ammar will be killed by a rebellious faction and army. But it were not we who killed 'Ammar." They said, "He was killed by our warriors." "No," he said, " 'Ammar was killed by 'Ali who brought him here and provided the causes of his death." 'Amr ibn 'As had two sons.

One of them was a worldly person like himself.