From the 'Treatise on the Purification of the Soul' (Risalat Tazkiyat al-Nafs): By the eminent Prince al-Hasan bin Makzun al-Sinjari—may God sanctify his soul and ennoble his resting place.

He says: 'The root of true Gnosis (ma'rifa) is a tree with a firm root and a towering branch; its fruit can only be attained by raising the hands of petition toward its pure branches. Its root is Pre-eternity (al-Azal), its branch is Everlastingness (al-Abad), and its fruit is Eternity (al-Sarmad). These are the three ranks which the scholars of Monotheism (Tawhid) expressed as the Meaning (al-Ma’na), the Veil (al-Hijab), and the Gate (al-Bab); and which the Sages expressed as the Creator (al-Bari), the Intellect (al-'Aql), and the Soul (al-Nafs). It is through the knowledge of these that all other things are known.'

He says: 'There is no path to knowing these stations except through Him; and the knowledge of Him is not valid except through His Essence (Dhat); and His Essence is not known except through Vision (ru’ya); and Vision is not possible except through His Manifestation (Tajalli). Yet, His manifestation cannot be perceived in its absolute entirety, because manifestation occurs according to the strength of the one gazing upon Him.'

The meaning of this is: 'The removal of the veil of darkness from the observer's sight, so that he may witness the Essence of the Manifesting One according to his own capacity,