The revelations of Islam began in 610 AD and lasted until 633, the Prophet's death.
Two phases are distinguished, the period of Mecca (610-622) and of Medina (622-633). Hijra took place in 622 when Mohammed (peace be upon him) and Muslims fled from Mecca to Medina. From that time Hijra calendar is calculated. The first period of Hijra was shadowed with wars. The unbelievers did their utmost to undermine the establishment of the Islamic State and launched repeatedly attacks on Medina. However, by the fifth year of the Hijra, it has been proved that the Islamic State cannot be defeated militarily. Under the above mentioned circumstances, the wicked designs of the disbelievers led them to start a campaign of vilification against the Holy Prophet and the Muslims in order to destroy the bulwark of morale that was helping them to defeat their enemies. Therefore the strategy was to attain the assistance of the hypocrites to spread slanders against the Holy Prophet and his followers so that the mushriks could exploit these to sow the seeds of discord among the Muslims and undermine their discipline.

The first opportunity for the use of the new strategy was afforded in Zil-Qa'dah 5 A. H. when the Holy Prophet married Hadrat Zainab (daughter of Jahsh), who was the divorced wife of his adopted son, Zaid bin Harithah. The Holy Prophet had arranged this marriage in order to put an end to the custom of ignorance, which gave the same status to the adopted son that was the right only of the son from one's own loins. The hypocrites, however, considered it a golden opportunity to vilify the Holy Prophet from inside the community, and the mushriks exploited it from outside to ruin his high reputation by this malicious slander. For this purpose fantastic stories were concocted and spread to this effect: "One day Muhammad (Allah's peace be upon him) happened to see the wife of his adopted son and fell in love with her; he maneuvered her divorce and married her." Though this was an absurd fiction it was spread with such skill, cunning and artfulness that it succeeded in its purpose; so much so that some Muslim traditionalists and commentators also have cited some parts of it in their writings, and the orientalists have exploited these fully to vilify the Holy Prophet. As a matter of fact, Hadrat Zainab was never a stranger to the Holy Prophet that he should see her by chance and fall in love with her at first sight. For she was his first cousin, being the daughter of his real paternal aunt, Umaimah, daughter of Abdul Muttalib. He had known her from her childhood to her youth. A year before this incident, he himself had persuaded her to marry Hadarat Zaid in order to demonstrate practically that the Quraish and the liberated slaves were equal as human being. As she never reconciled herself to her marriage with a liberated slave, they could not pull on together for long, which inevitably led to her divorce. The above mentioned facts were well known to all, yet the slanderers succeeded in their false propaganda with the result that even today there are people who exploit these things to defame Islam.

The second slander was made on the honor of Hadrat Ayesha, a wife of the Holy Prophet, in connection with an incident which occurred while he was returning from the Campaign against Bani al-Mustaliq. As this attack was even severer than the first one and was the main background of this Surah, we shall deal with it in greater detail. Let us say a few words about Abdullah bin Ubayy, who played the part of a villain in this attack. He belonged to the clan of Khazraj and was one of the most important chiefs of Al-Madinah. The people had even intended to make him their king a little before the Holy Prophet's migration there, but the scheme had to be dropped because of the changed circumstances. Though he had embraced Islam, he remained at heart a hypocrite and his hypocrisy was so manifest that he was called the "Chief of the Hypocrites". He never lost any opportunity to slander Islam in order to take his revenge. When in Sha'ban 6 A. H. the Holy Prophet learned that the people of Bani al-Mustaliq were making preparations for a war against the Muslims and were trying to muster other clans also for this purpose, he fore- stalled and took the enemy by surprise. After capturing the people of the clan and their belongings, the Holy Prophet made a halt near Muraisi, a spring in their territory. One day a dispute concerning taking water from the spring started between a servant of Hadrat Umar and an ally of the clan of Khazraj, and developed into a quarrel between the Muhajirs (immigrants) and the Ansar (Muslims of Madinah), but was soon settled. This, however, did not suit the strategy of Abdullah bin Ubayy, who also had joined the expedition with a large number of hypocrites. So he began to incite the Ansar, saying, "You yourselves brought these people of the quraish from Makkah and made them partners in your wealth and property. And now they have become your rivals and want domination over you. If even now you withdraw your support from them, they shall be forced to leave your city." Then he swore and declared, "As soon as we reach back Al-Madinah, the respectable people will turn out the degraded people from the city."
When the Holy Prophet came to know of this, he ordered the people to set off immediately and march back to Al-Madinah. The forced march continued up to noon the next day without a halt on the way so that the people became exhausted and had no time for idle talk. Though this wise judgment and quick action by the Holy Prophet averted the undesirable consequences of the mischief, Abdullah bin Ubayy got another opportunity for doing a far more serious and greater mischief, i. e. by engineering a "Slander" against Hadrat Ayesha, for that was a mischief which might well have involved the young Muslim Community in a civil war, if the Holy Prophet and his sincere and devoted followers had not shown wisdom, forbearance and marvelous discipline in dealing with it. In order to understand the events that led to the incident of the "Slander", we cite the story in Hadrat 'Ayesha's own words. She says :

"Whenever the Holy Prophet went out on a journey, he decided by lots as to which of his wives should accompany him. Accordingly, it was decided that I should accompany him during the expedition to Bani al Mustaliq. On the return journey, the Holy Prophet halted for the night at a place which was the last stage on the way back to Al- Madinah. It was still night, when they began to make preparations for the march. So I went outside the camp to ease myself. When I returned and came near my halting place, I noticed that my necklace had fallen down somewhere. I went back in search for it but in the meantime the caravan moved off and I was left behind all alone. The four carriers of the litter had placed it on my camel without noticing that it was empty. This happened because of my light weight due to lack of food in those days. I wrapped myself in my sheet and lay down in the hope that when it would be found that I had been left behind, a search party would come back to pick me up. In the meantime I fell asleep. In the morning, when Safwan bin Mu'attal Sulami passed that way, he saw me and recognized me for he had seen me several times before the Commandment about purdah had been sent down. No sooner did he see me than he stopped his camel and cried out spontaneously : "How sad! The wife of the Holy Prophet has been left here!" At this I woke up all of a sudden and covered my face with my sheet. Without uttering another word, he made his camel kneel by me and stood aside, while I climbed on to the camel back. He led the camel by the nosestring and we overtook the caravan at about noon, when it had just halted and nobody had yet noticed that I had been left behind. I learnt afterwards that this incident had been used to slander me and Abdullah bin Ubayy was foremost among the slanderers. (According to other traditions, when Hadrat Ayesha reached the camp on the camel, led by Safwan, and it was known that she had been left behind, Abdullah bin Ubayy cried out, 'By God, she could not have remained chaste. Look, there comes the wife of your Prophet openly on the camel led by the person with whom she passed the night.')

"When I reached Al-Madinah, I fell ill and stayed in bed for more than a month. Though I was quite unaware of it, the news of the "Slander" was spreading like a scandal in the city, and had also reached the Holy Prophet. Anyhow, I noticed that he did not seem as concerned about my illness he used to be. He would come but without addressing me directly, would inquire from others how I was and leave the house. Therefore it troubled my mind that something had gone wrong somewhere. So I took leave of him and went to my mother's house for better nursing.
"While I was there, one night I went out of the city to ease myself in the company of Mistah's mother, who was a first cousin of my mother. As she was walking along she stumbled over something and cried out spontaneously, 'May Mistah perish!' To this I retorted, 'What a good mother you are that you curse your own son -- the son who took part in the Battle of Badr.' She replied, 'My dear daughter, are you not aware of his scandal mongering?' Then she told me everything about the campaign of the "Slander".(Besides the hypocrites, some true Muslims also had been involved in this campaign, and among them who took leading part in it, were Mistah, Hassan bin Thabit, the famous poet of Islam, and Hamnah, daughter of Jahsh and sister of Hadrat Zainab). Hearing this horrible story, my blood curdled, and I immediately returned home, and passed the rest of the night in crying over it.

"During my absence the Holy Prophet took counsel with Ali and Usamah bin Zaid about this matter. Usamah said good words about me to this effect: 'O Messenger of Allah, we have found nothing but good in your wife. All that is being spread about her is a lie and calumny.' As regards Ali, he said, 'O Messenger of Allah, there is no dearth of women; you may, if you like, marry an other wife. If, however, you would like to investigate into the matter, you may send for her maid servant and inquire into it through her.' Accordingly, the maid servant was sent for and questioned. She replied, 'I declare on an oath by Allah, Who has sent you with the Truth, that I have never seen any evil thing in her, except that she falls asleep when I tell her to look after the kneaded dough in my absence and a goat comes and eats it.'

"On that same day the Holy Prophet addressed the people from the pulpit, saying: 'O Muslims, who from among you will defend my honor against the attacker of the person who has transgressed all bounds in doing harm to me by slandering my wife. By God, I have made a thorough inquiry and found nothing wrong with her nor with the man, whose name has been linked with the "Slander". At this Usaid bin Hudair (or Sa'd bin Mauz according to other traditions) stood up and said, 'O Messenger of Allah, if that person belongs to our clan, we will kill him by ourselves, but if he belongs to the Khazraj clan, we will kill him if you order us to do so.' Hearing this Sa'd bin 'Ubadah, chief of the Khazraj clan, stood up and said, 'You lie you can never kill him. You are saying this just because the person belongs to our clan of Khazraj. Had he belonged to your clan, you would never have said so.' Hadrat Usaid retorted, 'You are a hypocrite: that is why you are defending a hypocrite.' At this, there was a general turmoil in the mosque, which would have developed into a riot, even though the Holy Prophet was present there the whole time. But he cooled down their anger and came down from the pulpit."
But here we would only want to point out the enormity of the mischief that was engineered by Abdullah bin Ubayy: (1) It implied an attack on the honor of the Holy Prophet and Hadrat Abu Bakr Siddiq. (2) He meant to undermine the high moral superiority which was the greatest asset of the Islamic Movement (3) He intended to ignite civil war between the Muhajirs and the Ansar, and between Aus and Khazraj, the two clans of the Ansar.

The two slanderers played a decisive role in the development of women's clothing. Until the 5th year of the Hijab, it was not customary to wear the Hijab. And from here it is Sunnah.

But I would have a comment. It is important what is revealed from a person and to whom. It is a matter of decision whether we are showing ourselves as a biological being, an official person, a businessman, representative of an average of a given society or anything else. Every "show" has a particular circle that I tell about myself for that circle. One of the means to do this is the attire. The fashion doesn't go always parallel with that will. Therefore, we often face the dilemma of what to convey, the message, or the trend? I consider the message more important, but this is a private opinion.