God is the light of the heavens and the earth. The likeness of His light is as a niche, in- side the niche is a lamp, the lamp inside a glass.... Light upon light. God guides to His light whomsoever He will. In reality light is that which illuminates other than itself. Whatever does not illuminate another is not called light. The sun is light, the moon is light, and the lamp is light-not in the sense that they are bright in themselves, but in the sense that they illuminate others. Mirrors, water, jewels, and the like are not called light, even if they are bright by their own essences, for they do not il- luminate others. Now that this reality is known, know that God is the light of the heavens and the earth: It is God who is the brightener of the heavens and the earths for the faithful and the friends. It is He who gives form to bodies and illuminates spirits. All lights come forth from Him and abide through Him, some outward and some inward. Concerning the outward He says, “And We ap- pointed a blazing lamp” [78:13]. Concerning the inward He says, “Is he whose breast God has expanded for the submission, so he is upon a light from his Lord?” [39:22]. Although the outward light is bright and beautiful, it is subordinate to and servant of the in- ward light. The outward light is the light of sun and moon; the inward light is the light of tawḤīd and recognition. The light of sun and moon is lovely and bright, but at the end of the day it will be eclipsed and occulted. Tomorrow at the resurrection it will be opaque and enwrapped, according to His words, “When the sun is enwrapped” [81:1]. As for the sun of recognition and the light of tawḤīd, these rise up from the hearts of the faithful and will never be eclipsed or occulted, nor will they be overcome and enwrapped. They are a rising without setting, an unveiling without eclipse, and a radiance from the station of yearning. A poet has said, Surely the noonday sun sets at night, but the heart's sun never disappears. Know also that the outward lights are diverse in their levels. The first is the light of submission, and along with submission the light of self-purification.