They had their own principles and standards...
They had their own principles and standards, and they never mixed these with principles against their own; they showed their disgust with anyone who was tainted with sin. Ziyad ibn Abih killed one of them and then sent for the man's slave and enquired of him what kind of a man he had been. The slave said that he had never brought food for him during the day, nor laid out his bedding at night; during the day he had fasted and he had spent the nights in prayer.
Wherever they placed their footsteps, they referred back to their beliefs and they were devout in all their actions. They would kill to forward their beliefs.
'Ali (as) said of them Do not kill any Khawarij after me, because one who seeks the truth and errs is not the same as one who seeks falsehood and finds it.[^1] He meant that they were different from those around Mu'awiyah, for they wanted truth, but had fallen into error, Whereas those around Mu'awiyah were imposters from the start whose way was that of falsehood.
Thus if they were to kill the Khawarij after `Ali had gone it would be to the advantage of Mu'awiyah who was worse and more dangerous than them. It is necessary; before we go on to describe the other particularities of the Khawarij, to remember one point, since we are talking about their pretension to devotion, piety and asceticism.
One of the wonderful, distinctive and extraordinary points in the history of the life of 'Ali, whose like cannot be found, is his courageous and brave stand when fighting against these fossilized and haughty pietists. In front of people who clung to, and adorned themselves with, the externals of devotion, and whose faces affected truth, whose clothes were in tatters and who were professional worshippers, 'Ali drew his sword and subjected them Ali to its sharp edge.
Surely, if we had been in the place of his companions and had seen the face of these people, our feelings would have been moved, and we would have remonstrated with 'Ali about drawing swords against such people. This story of the Khawarij is one of the most edifying lessons for the history of Shi'ism in particular, and for the world of Islam in general.