Allah is the Light of the heavens and the earth. The allegory of His light is that of a pillar on which is a lamp. The lamp is within a glass. The glass is like a brilliant planet, fueled by a blessed tree, an olive tree, neither eastern nor western. Its oil would almost illuminate, even if no fire has touched it. Light upon Light. Allah guides to His light whomever He wills. Allah thus cites the parables for the people. Allah is cognizant of everything.