Allah is the light of the heavens and the earth. A likeness of His light is as a pillar on which is a lamp -- the lamp is in a glass, the glass is as it were a brightly shining star -- lit from a blessed olive-tree, neither eastern nor western, the oil whereof gives light, though fire touch it not -- light upon light. Allah hides to His light whom He pleases. And Allah sets forth parables for men, and Allah is Knower of all things --