Islamic revival (or Tajdid, also Sahwah) ( , also , "Islamic awakening") refers to a revival of the Islamic religion. Revivals (ẗajdid) have traditionally been a periodic occurrence throughout the Islamic world, led by a "reviver" or mujaddid who arrives at the beginning of every (Islamic) century, according to one hadith. The mujaddid will "fear none but God, and put a stop to (religious) "ignorance", "false innovations" and "a deterioration in following of the Sunnah".