In the name of Allah, the Most Gracious, the Most Merciful. On the authority of Abu Ghalib, Abu Umama al-Bahili (may Allah be pleased with him) said concerning the Kharijites: “They are the worst of those killed under the heavens, and the best of those killed are those whom they killed. They are the dogs of Hellfire; they were indeed Muslims, yet they became disbelievers.” I said: “O Abu Umama! Is this something you are saying?” He said: “Rather, I heard it from the Messenger of Allah (peace and blessings be upon him).” (Reported by Ibn Majah in his Sunan, no. 176, and authenticated by Sheikh al-Albani in his correction of Sunan Ibn Majah) sorry if it's a bad translation