A third group kept out of both camps altogether and stayed away from the turmoil.

A very large battle then broke out between ʿAlī and Muʿāwiyah at Ṣiffīn, in which ʿAmmār ibn Yāsir (may Allah be pleased with him) was killed—the same ʿAmmār about whom the Prophet ﷺ had said, “ʿAmmār will be killed by the transgressing faction.”

Shaykh al-Islām said: Some scholars have challenged the authenticity of the ḥadith, “ʿAmmār will be killed by the faction,” yet Muslim recorded it in his Ṣaḥīḥ and it appears in some manuscripts of al-Bukhārī. Even so, the fact that the transgressing faction killed ʿAmmār does not place them outside the fold of faith, for the Quran still calls them “brothers” despite the fighting and their aggression—especially when such aggression arose from a mistaken but sincere ijtihād (independent judgment).

The Shaykh added: Some of the leading Companions held that one should fight alongside the party in which ʿAmmār was found, while others believed one should refrain from fighting altogether. Those who supported fighting with ʿAmmār’s side cited this ḥadith, arguing that Allah has commanded fighting the faction that transgresses. Those who remained neutral relied on many authentic reports stating that sitting out the fitnah is better than engaging in combat.

The position of Ahl al-Sunnah wa-l-Jamāʿah is that the correct view lay with ʿAlī, yet they extend loyalty to all the Companions, acknowledge their precedence, companionship, and virtues, and remain silent about what occurred between them. May Allah be pleased with them all.

Concerning the fighting between ʿAlī and his opponents, Shaykh al-Islām reports that the people of deviant desires hold several views:
• The Khārijites declare both camps disbelievers.
• The Rāfiḍites pronounce disbelief upon everyone who fought ʿAlī.
• Ahl al-Sunnah, however, agree on the uprightness of all the Companions; after that, our scholars and others hold different opinions regarding who was correct and who erred. The first opinion is that ʿAlī (may Allah be pleased with him) was the one who had the truth on his side.