God is the Light of the heavens and the earth ; the likeness of His Light is as a niche wherein is a lamp ( the lamp in a glass , the glass as it were a glittering star ) kindled from a Blessed Tree , an olive that is neither of the East nor of the West whose oil wellnigh would shine , even if no fire touched it ; Light upon Light ; ( God guides to His Light whom He will . ) ( And God strikes similitudes for men , and God has knowledge of everything . )