Overall meaning : We have sent down to you verses that are clear and clearly show the truth, as well as accounts of the nations before you to learn lessons from, and an admonition for the righteous who obey Allah’s commands.
Allah is the light of the heavens and the earth and the sole guide of everyone in them. His light in the heart of the believer is like a niche in which there is a lamp. The lamp is enclosed within a crystal, so luminous as though it were a pearl-like star. The lamp is lit from the oil of a blessed olive tree which nothing whatsoever screens it from the sun: It is neither eastern (getting sun rays only in the morning) nor western (getting sun-rays only in the evening), making its oil purer, more superior and more luminous. Its very oil is so pure that it would almost give light of itself although no fire touches it. Light upon light: The light of the fire combined with that of the oil and the crystal cover, and its reflection from the niche. Such is the believer’s heart when illuminated by Allah’s guidance. Allah guides to His light whomever He wills of His servants. Allah sets forth parables for mankind. He has knowledge of all things, and nothing is hidden from Him.