both outwardly and inwardly, necessitates for the Knower (arif) hesitation and punishment through the dark veils, while rejecting the obligatory necessitates eternal [punishment] in the fire of hell, because it is disbelief (kufr); and no knower (arif) shall enter the supreme kingdom without performing all the mandatory duties. For the supererogatory (nafila) is in reality legislated for the knower besides the standing and other [acts]. Toward this, the indication occurred in the Almighty’s saying: "And from the night, pray with it as additional worship (nafila) for you; perhaps your Lord will resurrect you to a praised station" 1 .
By "the night," He means the cycle of concealment (dawr al-satr) in which the sun of Truth is hidden by the darkness of falsehood in the world of temperament. That which was made obligatory of the night prayer (tahajjud) is the knowledge of pure monotheism, free from fabrication and the mixture of doubt. Since the supererogatory is likened to the obligatory, it is, according to the knower, attached to it and necessary for whoever knows the esoteric meaning of the obligatory prayer.