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. | The Mysteries of Purification by Abu Hamid Al-ghazali, Paperback | Indigo Chapters