We are pointing out some ahadith from Sahih Bukhari and Sahih Muslim regarding the Khawarij, as they were a part of authentic Islamic history. How often is it that we see sects accusing each other of being Khawarij, so we are shedding some light upon this matter.
We have summed up all their characteristics in the end; the readers can go directly to them while we would be narrating the entire hadiths that state from where all this started.
Jabir b. Abdullah reported that a person came to the Messenger of Allah (SallAllah-u-Alaihi-wa-Sallam) at Ja'rana on his way back from Hunain, and there was in the clothes of Bilal some silver. The Messenger of Allah (SallAllah-u-Alaihi-wa-Sallam) took a handful out of that and bestowed it upon the people. He (the person who had met the Prophet at Ja'rana) said to him: Muhammad, do justice. He (the Holy Prophet) said: Woe be upon thee, who would do justice if I do not do justice, and you would be very unfortunate and a loser if I do not do justice. Upon this Umar b. Khattab (Allah be pleased with him) said: Permit me to kill this hypocrite. Upon this he (the Holy Prophet) said: May there be protection of Allah! People would say that I kill my companions. This man and his companions would recite the Qur'an but it would not go beyond their throat, and they swerve from it just as the arrow goes through the prey.
[Sahih Muslim: Book 005, Number 2316]
In one narration the words are:
A person among the people then sought permission (from the Holy Prophet) for his murder. According to some, it was Khalid b. Walid who sought the permission. Upon this the Messenger of Allah (SallAllah-u-Alaihi-wa-Sallam), said: From this very person's posterity there would arise people who would recite the Qur'an, but it would not go beyond their throat; they would kill the followers of Islam and would spare the idol-worshippers. They would glance through the teachings of Islam so hurriedly just as the arrow passes through the pray. If I were to ever find them I would kill them like 'Ad.[Sahih Muslim: Book 005, Number 2318]
Another narration explains the event:
That man then returned. Khalid b. Walid then said: Messenger of Allah, should I not strike his neck? Upon this he (the Holy Prophet) said: Perhaps he may be observing the prayer. Khalid said: How many observers of prayer are there who profess with their tongue what is not in their heart? Upon this the Messenger of Allah (SallAllah-u-Alaihi-wa-Sallam) said: I have not been commanded to pierce through the hearts of people, nor to split their bellies (insides). He again looked at him and he was going back. Upon this he (the Holy Prophet) said: There would arise a people from the progeny of this (man) who would recite the Qur'an glibly, but it would not go beyond their throats; they would (hurriedly) pass through (the teachings of their) Deen just as the arrow passes through the prey. I conceive that he (the Holy Prophet) also said this: If I find them I would certainly kill them as were killed the (people of) Thamud.
[Sahih Muslim: Book 005, Number 2319]

This narration tells us that it was both of the companions asked the permission.

This hadith has been narrated through another chain of transmitters and (the narrator) made a mention of elevated forehead, but he made no mention of tucked-up loin cloth and made this addition:" There stood up 'Umar b. Khattab (Allah be pleased with him), and said: Should I not strike his neck? Upon this he said: No. Then he turned away, and Khalid the Sword of Allah stood up against him, and said: Prophet of Allah. Shall I not strike off his neck? He said, No, and then said: A people would rise from his progeny who would recite the Book of Allah glibly and fluently. 'Umar said: I think he (the Holy Prophet) also said this: If I find them I would certainly kill them like Thamud."
[Sahih Muslim: Book 005, Number 2320]

Other narrations regarding the Khawarij state that the Prophet SallAllah-u-Alaihi-wa-Sallam said: There would arise in this nation a people and you would hold insignificant your prayers as compared with their prayers. And they would recite the Qur'an which would not go beyond their throats and would swerve through the Deen (as blank) just as an (swift) arrow passes through the prey. The archer looks at his arrow, at its iron head and glances at its end (which he held) in the tip of his fingers to see whether it had any stain of blood.
[Sahih Muslim: Book 005, Number 2322]

The Messenger of Allah (SallAllah-u-Alaihi-wa-Sallam) said: Leave him, for he has friends that everyone among you would consider his prayer insignificant as compared with their prayer, and his fast as compared with their fasts. They would recite the Qur'an but it would not go beyond their collarbones. They would pass through (the teachings of Islam so hurriedly) just as the arrow passes through the prey. He would look at its Iron head, but would not find anything ticking) there. He would then see at the lowest end, but wou