It is narrated from Uthman Shahham, he says: Muslim bin Abi Bakrah narrated to us that he asked him whether he had heard any hadith regarding the Khawarij? He said: I heard my father, Sayyiduna Abu Bakrah (may Allah be pleased with him), say that the Noble Prophet (peace and blessings be upon him) said: Beware! Soon there will arise from my Ummah people who will be harsh and severe in religious matters, their tongues will be very skilled with the Qur'an, but it will not go below their collarbones. When you see them, kill them. Then I say again, when you see them, kill them. The one who kills them will be deserving of reward.

It is narrated from Sayyiduna Abu Tufail (may Allah be pleased with him) that during the time of the Messenger of Allah (peace and blessings be upon him), a son was born to a man. He brought the child to the service of the Noble Prophet (peace and blessings be upon him), and the Prophet (peace and blessings be upon him) took hold of the skin of the child’s face and prayed for blessings for him. As a result, hair grew on the child’s forehead in the shape of a bow, and the child grew up. When the era of the Khawarij came, the child inclined towards them and began to love them, so the hair on his face fell off. Seeing this, his father caught him, imprisoned him, and kept him confined, fearing that he might fully join them. Sayyiduna Abu Tufail (may Allah be pleased with him) says: We went to him and gave him advice and admonition, and in our words we also said to him,“Do you not see that the blessing of the prayer of the Messenger of Allah (peace and blessings be upon him) has fallen from your forehead?”We continued to admonish him until he turned away from the opinion of the Khawarij. Allah Almighty accepted his repentance, and after that, hair grew again on his forehead.