Question: Nûr [light, halo] is a creature. Therefore, does it cause blasphemy, disbelief to use it to refer to Allah?
ANSWER
The word nûr cannot be used to refer to Allah if you mean “light” by it because nûr and light, too, have been created by Him, that is, they are His creatures. A creature cannot be the Creator. It is not permissible to describe Allahu ta’âlâ by likening Him to a thing. That it is wrong to use the word nûr to refer to Allah without knowing the ta’wîl [explaining away] of the word nûr that appears in the âyat “Allahu nûrus-samâwât-i wal-ard” of the Nûr Sûra is explained in the book Mishkat-ul anwar by Hadrat Imâm-i Ghazâlî.

An-Nûr is one of the Beautiful Names of Allahu ta’âlâ, but it does not mean “light” that we all know (it does not mean the physical light that the eyes perceive). It means the One who enlightens the worlds. Just as one of the Names of Allahu ta’âlâ is Nûr, so one of the names of our master the Prophet is Nûr. However, the latter, which is used in the sense of brightness and light, is completely different from the former.

The explanations given by Islamic scholars concerning nûr are as follows:
He is the One who has created and who governs the sun, the moon, and stars, which are the sources of light for the earth and the sky. The Creator of the light that exists in all planets is Allahu ta’âlâ. He is not the One who is light for them. If a spark from the nûr that surrounds the ‘Arsh comes to the earth, the earth would burn to ashes. Nûr is a state which enables us to see visible objects, and in this sense the word nûr cannot be used for Allahu ta’âlâ. But it can be used in the figurative sense of the word. For example, an enlightening book denotes a book that guides a person to the right path. Likewise, it means that Allah, too, is the One who enlightens the heavens and the earth, that is, the One who keeps the earth and the heavens under His command. A cultured person, for instance, is called “the light of his or her tribe.”

In Arabic it is said, “You filled me with nûr.” In English it is said, “You enlightened me,” which means “You informed me.” Also, the word nûr refers to the eyes because of the connection between light and the eyes. It also refers to basîrah [insight, perceptivity, discernment], because understanding becomes acuter with it.

The meanings of some verses containing the word nûr are as follows:
(Allah is the Nûr [the One who illuminates] of the heavens and the earth.) [Sûrat-un-Nûr, 35]

(The one to whom Allah does not give nûr cannot become a nûr [enlightened].) [Sûrat-un-Nûr, 40]

(Allah is the Friend of the Believers. He brings them out from darkness [disbelief] into nûr [hidâyah]. [He delivers them from the darkness of disbelief and makes them attain the light of îmân.] The friends of disbelievers are tâghût. They bring them out from the nûr [îmân] into darkness [disbelief].) [Sûrat-ul-Baqara, 257]

(An evident Nûr [the Qur’ân] has come to you from your Rabb.) [Sûrat-un-Nisâ’, 174]

(A Nûr [Prophet] and an evident Book [the Qur’ân] have come to you from Allah.) [Sûrat-ul-Mâ'ida, 15]

(Praise belongs to Allah, who created the heavens and the earth and who brought into being zulmat [night, disbelief, ignorance] and nûr [daytime, îmân, knowledge].) [Sûrat-ul-An‘âm, 1]

(Not equal are the blind and the seeing [Believers and disbelievers, scholars and ignoramuses], the zulmat and the nûr [falsehood and truth], the shade and the heat [Jannat and Jahannam]. Nor are the living and the dead. Certainly, Allah makes whomever He wills hear. You cannot make those who are in the graves [those who are obstinate disbelievers] hear. You are only a warner.) [Sûrat-u Fâtir, 19-22]

(The earth [the place of Mahshar] shines with the nûr [justice] of your Rabb.) [Sûrat-uz-Zumar, 69]

(For those who believe in Allah and His Messenger, there are nûrs and rewards reserved at their Rabb.) [Sûrat-ul-Hadîd, 19]

(O you who believe! Guard yourselves against violating Allah’s commandments and believe in His Messenger; Allah will then bestow His compassion upon you doubly and will provide for you a nûr, by the light of which you will walk.) [Sûrat-ul-Hadîd, 28]

(They want to extinguish the nûr [religion] of Allah with their mouths [with such evil utterances and slanders as “The Qur’ân is a poem” or “It is sorcery”]. But Allah will perfect His nûr [His religion], even if disbelievers are averse to it.) [Sûrat-us-Saff, 8]

As is seen, the word nûr has various meanings; however, you cannot use it to refer to Allah if you mean to liken Him a creature with that word.