The kharajites (
Arabic:
khawarij "To go out") were the first
sect to split from the
ummah in
Islam. Originally supporters of
Ali , they split when Ali was about to face off with
Mu'awiya over who should be
caliph (the
first fitnah). They were engaged in battle, and Muawiya requested arbitration. Ali granted it, and kharajites responded with a quotation from the
Qur'an,
La hukma illa lilla "There is no judgement except
Allah."
Later, Ali sent Ibn Abbas to debate with them, and he pointed out all the times which a judge was brought in to settle disputes under Islamic law, such as disputes between husband and wife. As a result, about 3,000 of the 30,000 kharajites returned to the fold. The rest remained infuriated with Ali that a supposed leader of the faithful would submit to a judge. Ali was murdered by a kharijite.
The Prophet (SAW) said in a hadith:
One of you would hold insignificant your own prayer compared with their (the Khawarij, according to every scholar I have seen) prayer, and his qiyam (standing erect before the ruku) compared with their qiyam, his recitation (of the Qur'an) compared with their recitation. They will recite the Qur'an but it will not go beyond their throats, and they pass through religion without a mark.
A characteristic of them is that they take verses from the Qur'an intended for the
kuffar and apply them to the the believers. Ali was asked about them and said: (when asked if they were hypocrites) "No, the hypocrites only think of Allah a little, they think of Allah all the time." (when asked if they were unbelievers) "No, they are our brothers who have transgressed against us."
I have heard another account of Ibn Abbas's speaking to the khawarij which says that 20,000 joined Ali, and only 4,000 remained.