God is the light of the heavens and the earth. Imagine a concave mirror behind a lamp which is placed inside a glass container. Imagine this container being like a bright, pearl-like star. Imagine the lamp being fueled by a blessed oil-producing tree, that you cannot find neither in the east nor in the west. Its oil is almost self-radiating; needs no fire to ignite it. Light upon light is the God’s light with which He guides whoever He wills. God thus explains (difficult to understand matters) so that mankind have some idea. Know that God knows everything.