1. Certainly, the by referring to Allah as light, the Qur’an does not intend to identify Him as a physical and sensory light because the sensible light is a part of the accident characteristic of matter whereas there are numerous arguments which negate the physicality of God, the Exalted, and which forbid us from considering God as a sensible and material light.
In addition, there are many Quranic verses which negate any similarity between God and anything else. Hence, if God has been described as being “the light of the Heavens and the earth”, the term “light” which refers to God is not and cannot be the sensory light.
2. Light is something which makes things visible; which is itself manifest and helps make other things manifest. The human mind conceives light in this very sense. Absence of light is termed darkness, invisibility and obscurity. On the other hand, when there is visibility and things become exposed to view, man says there is light. Allah has been called ‘Light’ in this basic sense. This conception of light has nothing to do with the reality of the meaning for which human mind has coined this word. If we analyze the meaning of light in relation to God, it would be correct to use for spiritual matters in the sense that they illuminate the soul. For example, the word “Eman” has been termed as “light” in the Quran which is granted to a believer.
3. Since God is manifest and clear and He is the Creator and the Illuminator of the heavens and the earth, it is correct to use the word “light” for God. In fact, it is the existence of everything that is the cause of its manifestness to others; the highest form of light is therefore existence itself. Moreover, since the existence of contingent beings depends on the bestowal of existence by the Truth, the Supreme, He is the most complete instance of light. It is He Who is essentially manifest and also makes manifest all other-than-him. All other existents become manifest and existent by virtue of Him.
4. By the expression “the heavens and the Earth”, what is intended is the entirety of the world of existence – all the celestial and the terrestrial existents; the apparent and the hidden worlds. “The heavens and the earth” does not merely signify the sky above and the Earth that we inhabit. Therefore, the meaning of the verse is that Allah is the Light of the entire universe. The reason why the verse has employed this word in lieu of the Creator is to point to the fact that just as light is itself visible and does not need anything else to make it visible, and it is light itself that illuminates all other things, likewise Allah has no creator and there is no other agent that could shed light on Him. He is a manifest, clear and self-evident existence. There is no need for formulating reasoning to prove His existence.
As propounded by the Gnostics in following the mystical teachings of the Prophets and the Imams, Allah is manifest to the highest degree; He is absolutely clear, and hence there is no need for the mediation of His creatures to reveal Him. In other words, in order to reason for the existence of Allah, one should utilize the argument of cause rather than the argument of effect.
Without the light of the Divine Essence, the shadow of non-existence would envelope all things; the resulting darkness would not be like that of the night (rather it would be the darkness of non-existence).
Hence, it must be said that Allah is absolute light. In comparison to Him, there is no other light. All other lights in comparison to Him are darkness. For the only existent Who is by His essence manifest and manifesting, is Allah. All other things that are manifest and that illuminate other creatures are by their essences dark. It is Allah Who has bestowed on them that feature. If He is not seen, it is because He is obscured by the intensity of His light.
5. Another point that can be inferred from this verse is that we refer to Allah as light, not as “the greatest light”, which implies that there are other lights as well, some more bright and others less bright, and that Allah is the greatest. According to the Qur’an, there is only one light and that is Allah, and everything else is dark and non-existent. It is true, however, that in comparing the creatures together, some are light and some are not – for instance, knowledge, faith, intellect etc., are light, but have all derived their light from Allah. Thus in comparison to Allah, there is no other light, or in other words, He is “the Light of Lights. That is, He is the light of all lights rather than being the greatest light. Therefore, the belief that Allah is the greatest light, that He is of the sensory lights but the brightest and the most intense – reputedly attributed to the Manicheans – is false.
6. There are different sayings, traditions and narratives in the interpretations concerning this verse. For information about them, one should refer to relevant books, exegesis (commentaries) and other textual sources.