God is the Light of the heavens and the earth. The parable of His Light is as a niche in which there is a lamp. The lamp is in a glass. The glass is as if it had been a glittering star, kindled from a blessed olive tree, neither eastern nor western, whose oil of the olive is about to illuminate although no fire touches it. Light on light, God guides to His Light whom He wills! And God propounds parables for humanity, and God is Knowing of everything.