Let a person of insight reflect on this great verse and on how it can be applied according to this noble meaning. God mentions His light in the heavens and on earth, and His light in the hearts of His believing servants. There is intelligible light, perceived by insight, illuminating inner visions and hearts [al-nur al-ma`qul al-mashhud bi 1-bas.a'ir wa 1-qulub]. And there is the physical light [al-nur al-mah.sus], perceived by the faculty of sight, illuminating the upper and the lower regions of the world: two sublime lights, one more sublime than the other. When physical light is absent from some place, no human being or animal can live there. Animal life is engendered only where there is light. It cannot thrive in dark places where no light shines. And so, a people for whom the light of revelation and faith has gone out, and a heart in which this light has gone out, must be dead, no more alive than the most lifeless place on earth.

Commentary on the Verse of Light
Imam Ibn ul Qayyim al Jawziyyah
The Invocation of God - Al-Wabil al-Sayyib min al-Kalim al-Tayyib © 2000, Michael Abdurrahman Fitzgerald & Moulay Youssef Slitine (Translators) Islamic Texts Society, UK