Allah is the Light of the heavens and the earth. The parable of His Light is as (if there were) a niche and within it a lamp, the lamp is in glass, the glass as it were a brilliant star, lit from a blessed tree, an olive, neither of the east (i.e. neither it gets sun-rays only in the morning) nor of the west (i.e. nor it gets sun-rays only in the afternoon, but it is exposed to the sun all day long), whose oil would almost glow forth (of itself), though no fire touched it. Light upon Light! Allah guides to His Light whom He wills. And Allah sets forth parables for mankind, and Allah is All-Knower of everything.