One of the traits of the Khārijites is that they are attached primarily to the Qurʾān in the development of their doctrine. The reason for this is that it allows them to interpret the Qurʾān through their own opinions without recourse to the Sunnah. Ibn Taymiyyah said:

When the foundation of innovations is known, then the foundation of the statement of the Khārijites is that they expel [from Islām] on account of sins, they believe to be a sin what is not a sin and they hold that the Book is to be followed but not the Sunnah which [appears to them to] oppose what is apparent [to them] from the Book, even it was related by large-scale successive transmission.

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