The Harūrī (Arabic: الحرورية) were an early Muslim sect from the period of the Four Rightly-Guided Caliphs (632-661 CE), named for their first leader, Habīb ibn-Yazīd al-Harūrī. The Harūrī were one branch of the Khārijī "Rejectors" movement, so called because they rejected ‘Alī's right to the Caliphate. While originally members of the "Party of ‘Alī", they turned against him when he agreed to arbitration regarding the issue of leadership and a Harūrī assassinated ‘Alī while he was praying on 21 Ramaḍān in 661 CE.
In Tafsir ibn Kathir, in the commentary of the ayat 18:103-104, "...Say, shall We tell you the greatest losers in respect of (their) deeds? Those whose efforts have been wasted in this life while they thought that they were acquiring good by their deeds!...", Imam Bukhari recorded from Amr that Musab who said, "I asked my father --meaning Sa`d ibn Abi Waqqas-- about Allah's Saying, "Say, shall We tell you the greatest losers in respect of (their) deeds!", 'Are they the Haruriyyah?' He said, "No, they are the Jews and Christians. As for the Jews, they disbelieved in Muhammad and as for the Christians, they disbelieved in Paradise and said that there is no food or drink there, and the Hururiyyah are those who break Allah's Covenant after ratifying it."
Ali bin Abu Talib is quoted to have said that it is the Hururiyyah.
While the Harūrī are primarily notable because one of their members assassinated the Fourth Caliph, this is not the only reason they have drawn historical interest. The issue of political leadership and divine power that has been a hot topic for Muslims since colonialism and most acutely in post-colonial Islamic movements and states is paralleled in many ways by the "problem" of Khārijī movements in early Islam. As Khaled Abou El Fadl writes,
Anecdotal reports about the debates between 'Ali and the Khawarij reflect unmistakable tension about the meaning of legality and the implications of the rule of law. In one such report members of the Khawarij accused 'Ali of accepting the judgment and dominion (hakimiyya) of human beings instead of abiding by the dominion of God's law. Upon hearing of this accusation, 'Ali called on the people to gather around him and brought out a large copy of the Qur'an. 'Ali touched the Qur'an while instructing it to speak to the people and inform them about God's law. Surprised, the people who had gathered around 'Ali exclaimed, "What are you doing? The Qur'an cannot speak, for it is not a human being!" Upon hearing this, 'Ali exclaimed that this was exactly his point. The Qur'an, 'Ali explained, is but ink and paper, and it does not speak for itself. Instead, it is human beings who give effect to it according to their limited personal judgments and opinions.
Such stories are subject to multiple interpretations, but this one points most importantly to the dogmatic superficiality of proclamations of God's sovereignty that sanctify human determinations. Notably, the Khawarij's rallying cry of "Dominion belongs to God" or "The Qur'an is the judge" (la hukma illa li'llah or al-hukmu li'l-Qur'an) is nearly identical to the slogans invoked by contemporary fundamentalist groups. But considering the historical context, the Khawarij's sloganeering was initially a call for the symbolism of legality and the supremacy of law that later descended into an unequivocal radicalized demand for fixed lines of demarcation between what is lawful and unlawful.
Also of interest to scholars is the Harūrī position that it was permissible to entrust the Imamate to a woman if she was able to carry out the required duties. The founder's wife, Ghazāla al-Harūriyya, commanded troops; in this she followed the example of Juwayriyya, daughter of Abu Sufyan, at the battle of Yarmuk. In one battle between Ghazāla and the famous Umayyad general Hajjāj ibn-Yūsuf, he had to retreat.