He was chosen the leader of the Kharjis, when they separated from Hazrat Ali during the battle of Siffin. When Mu'awiya proposed to settle the differences arising out of the murder of Hazrat Usman by referring it to two arbitrators who would judge 'according to the Qur'an', while the majority of the people accepted the proposal, one group of soldiers mainly belonging to the tribe of Tamim, protested and withdrew to Kufa, where they elected Wahb as their chief. The dissenters, who had left Hazrat Ali, were called Kharjis (went out).