A lucid and profound exposition of the gnostic science that lies at the heart of sufism. A Guide Book to Khalwa, spiritual retreat, preparing the murid by the doctrine of unity for the experiences that will befall him in the self-shattering annihilation he desires. Shaykh al-'Alawi has taken ibn al-'Ashir's verse poem, itself a summation of Islamic teachings, and made it a vehicle for maiking plain the unitary knowledge, the hidden doctrine, that lies beneath every phenomenon of outer wisdom. Thus he is able to unveil from even the lowest functions of cleaning the body an exalted meaning which indicates the Oneness of his Lord. Above all, this is a book of action constantly returning the gnostic traveller to slavehood, covering over his secrets and concealing the intoxicating knowledge that he gained. It confirms the simple qualities of correct moral behaviour that are the hallmark of the great.