In order to understand this, it is necessary to recall the earlier explanation, in section #17#, where it was explained that the Essentially Existing One is of the mystical meaning of essence, something of which we have no grasp. This inability to grasp essence applies even to physical essences, and even to our own essences; all the more so for the Essentially Existing One. The world of Atzilut is the mystical meaning of form, while the three worlds of Beria, Yetzira, and Asiya are the mystical meaning of substance, and the illumination of Atzilut in Beria, Yetzira, and Asiya is the mystical meaning of form enclothed in substance.