यह सूरा (एक-नूर) कविता 35 से, इसका नाम, एक नूर लेता है।

The consensus of opinion is that it was sent down after the Campaign against Bani al-Mustaliq and this is confirmed by vv. 11-20 that deal with the incident of the "Slander", which occurred during that Campaign. But there is a difference of opinion as to whether this Campaign took place in 5 A. H. before the Battle of the Trench or in 6 A. H. after it. It is important to decide this issue in order to determine whether this Surah was sent down earlier or Surah Al- Ahzab(XXXIII), which is the only other Surah containing the Commandments about the observance of purdah by women. Surah Al-Ahzab was admittedly sent down on the occasion of the Battle of the Trench. Now if this Battle occurred earlier, it would mean that the initial instructions in connection with the Commandments of purdah were sent down in Surah Al-Ahzab and they were complemented later by the Commandments revealed in this Surah. On the other hand, if the Campaign against Bani al-Mustaliq occurred earlier, the chronological order of the Commandments would be reversed, and it would become difficult to understand the legal wisdom and implications of the Commandments of purdah.

According to Ibn Sa'd, the Campaign against Bani al Mustaliq took place in Shaban 5 A. H. and the Battle of the Trench in Zil- Qa'dah the same year. This opinion is based on some traditions from Hadarat Ayesha about the events connected with the "Slander" in which she refers to a dispute between Hadrat Sa'd bin 'Ubadah and Sa'd bin Mu'az. Hadrat Sa'd bin Mu'az, according to authentic traditions, died during the Campaign against Bani Quraizah, which took place immediately after the Battle of the Trench. It is, therefore, evident that he could not be present in 6 A. H. to take part in a dispute about the "Slander".

On the other hand, Muhammad bin Ishaq says that the Battle of the Trench took place in Shawwal 5 A. H. and the Campaign against Bani al-Mustaliq in Sha'ban 6 A. H. This opinion is supported by many authentic traditions from Hadrat Ayesha and others. According to these traditions, (1) the Commandments about purdah had been sent down in Surah Al-Ahzab before the incident of the "Slander", (2) the Holy Prophet had married Hadrat Zainab in Zil-Qa'dah 5 A. H. after the Battle of the Trench, (3) Hamnah, sister of Hadrat Zainab, had taken a leading part in spreading the "Slander", just because Hadrat Ayesha was a rival of her sister. All this evidence supports the view of Muhammad bin Ishaq.

Now let us consider the two opinions a little more closely. The only argument in favor of the first opinion is the mention of the presence of Hadrat Sa'd bin Mu'az in a dispute connected with the incident of the "Slander". But this argument is weakened by some other traditions from Hadrat Ayesha, in which she mentions Hadrat Usaid bin Hudair instead of Hadrat Sa'd bin Mu'az in this dispute. It may, therefore, be assumed that there has been some confusion regarding the two names in reporting the traditions. Moreover, if we accept the first opinion, just because of the mention of the name of Hadrat Sa'd bin Mu'az in some traditions, we encounter other difficulties that cannot be resolved in any way. For, in that case, we shall have to admit that the revelation of the Commandments of purdah and the Holy Prophet's marriage with Hadrat Zainab had taken place even earlier than the Battle of the Trench. But we learn from the Qur'an and many authentic traditions that both these events happened after that Battle and the Campaign against Bani Quraizah. That is why Ibn Hazm, Ibn Qayyim and some other eminent scholars have held the opinion of Muhammad bin Ishaq as correct, and we also hold it to be so. Thus, we conclude that Surah Al Ahzab was sent down earlier than Surah An-Nur, which was revealed in the latter half of 6 A. H. several months after Surah Al Ahzab.