Ubayy ibn Ka`b said, 'the similitude of His light [takes place in] the Muslim's heart.' [Ibn Kathir, 3:464] This light, which He has placed in the heart, comes from gnosis, love, faith and the remembrance of God. It is the light that He has sent down to His servants, by which He gives them life, and by which they walk among people. Its origin is in their hearts, but then He strengthens and increases it until it appears upon their faces, limbs, bodies, even their clothes and dwellings.