When Amīr al-mu’minīn showed his intention to fight the Khārijites he was told that they had crossed the bridge of Nahrawan and gone over to the other side. Amīr al-mu’minīn said :
وقال (عليه السلام) لمّا عزم على حرب الخوارج وقيل له: إن القوم قد عبروا جسر النهروان