Evaluating the narrators of hadith began in the generation following that of the Companions based upon the statement of Muhammad Ibn Sirin, "They did not previously inquire about the "isnad". However, after the turmoil occurred they would say, 'Name for us your narrators.' So the people of the Sunnah would have their hadith accepted and the people of innovation would not." The "turmoil" referred to is the conflicting ideology of the Shias after the passing of the Prophet, and later the Kharijites that had emerged at the time of the third Sunni Caliph Uthman ibn Affan's assassination and the social unrest of the Kharijites in opposition to the succeeding rulers, Ali and Muawiyah. The death of Uthman was in the year 35 after the migration.