A Mujaddid, according to the popular Muslim tradition, refers to a person who appears at the turn of every century of the Islamic calendar to revive Islam, remove from it any extraneous elements and restore it to its pristine purity. A mujaddid might be a caliph, a saint (wali), a prominent teacher, a scholar or some other kind of influential person.[citation needed] The concept is based on the following Prophetic tradition (hadith): Abu Hurairah narrated that the Islamic prophet Muhammad said; “Allah shall raise for this Ummah at the head of every century a man who shall renew (or revive) for it its religion.”

—Sunan Abu Dawood, Book 37: Kitab al-Malahim [Battles], Hâdith Number 4278.[1] ASHFAQ AHMED