Qur'anic verses - The Light of heavens and earth:

Layer upon layer of allegorical truth about spiritual mysteries-No notes can do adequate justice  to its full meaning. It is an endless chain of illumination in which ordinary knowledge dissolves as if it were ignorance.

The physical eye sees by the physical light; the spiritual eye sees by Revelation. There is a world invisible, with Light of its own, quite different from the world visible, with its own physical light.

The physical light is but a reflection of the true Light in the world of Reality, and that true Light is God, Who is Light in and by Himself, not a light kindled from other lights.

We can only think of God in terms of our phenomenal experience, and in the phenomenal world, light is the purest thing we know. But physical has drawbacks incidental to its physical nature: it depends on external source; it is an unstable passing phenomena; it depends on space and time. The perfect Light of God is free from any such defects.