↑Battle of Ṣiffīn, Encyclopædia Britannica, retrieved on April 17, 2019. "...ʿAlī gathered support in Kūfah, where he had established his centre, and invaded Syria. The two armies met along the Euphrates River at Ṣiffīn (near the Syrian-Iraqi border), where they engaged in an indecisive succession of skirmishes, truces, and battles, culminating in the legendary appearance of Muʿāwiyah’s troops with copies of the Qurʾān impaled on their lances—supposedly a sign to let God’s word decide the conflict." Archived at the Wayback machine
↑Muʿāwiyah I, Encyclopædia Britannica, retrieved on April 17, 2019. "As a kinsman of the slain caliph ʿUthmān, Muʿāwiyah bore the duty of revenge. Because ʿAlī neglected to apprehend and punish ʿUthmān’s murderers, Muʿāwiyah regarded him as an accomplice to the murder and refused to acknowledge his caliphate. Thereupon ʿAlī marched to the Euphrates border of Syria and engaged Muʿāwiyah’s troops at the famous Battle of Ṣiffīn (657). Muʿāwiyah’s guile turned near defeat into a truce. Resorting to a trick that played upon the religious sensibilities of ʿAlī’s forces, he persuaded the enemy to enter into negotiations that ultimately cast doubt on the legitimacy of ʿAlī’s caliphate and alienated a sizable number of his supporters." Archived at the Wayback machine
↑ 12Ibn Yaqubi, Ahmad. Tarikh Al Yaqubi. Armenia: Ahmad Ibn Yaqubi. 872. səh. 188. ISBN9786136166070.
↑ 12Muir, William. The Caliphate, its Rise and Fall. London: William Muir. 1891. səh. 261.