God is the light of the heavens and the earth; His light is as a niche in which is a lamp, and the lamp is in a glass, the glass is as though it were a glittering star; it is lit from a blessed tree, an olive neither of the east nor of the west, the oil of which would well-nigh give light though no fire touched it,- light upon light!- God guides to His light whom He pleases; and God strikes out parables for men, and God all things doth know.