Qur'an, Al-Nour, Surah 24:35a
God is the light of the heavens and the earth. His light is like a niche that holds a lamp; it is like a lamp which contains a crystal as bright as a star. It is kindled from a blessed tree, an olive tree that belongs neither to the east nor to the west. Its oil would almost shine, even with no fire touching it. It is light upon light. God guides towards his light all whom he chooses.