Mysteries of Purification, Paperback by Al-ghazali, Abu Hamid; Aresmouk, Mohamed Fouad (TRN); Fitzgerald, Michael Abdurrahman (TRN), ISBN 1941610315, ISBN-13 9781941610312, Like New Used, Free shipping in the US In The Mysteries of Purification (Kitab asrar al tahara), the third of the forty books of the Revival of the Religious Sciences (Ihya’ ‘ulum al-din), Abu Hamid al-Ghazali explains the fundamentals of the purification that is necessary in order to perform the five daily prayers.