The Surah takes its name from verse 4 in which the word hujurat has occurred.
Traditions show and the subject matter of the Surah also supports the same that this Surah is a collection of the commandments and instructions sent down on different occasions, which have been put together because of the relevancy of the theme. Moreover, the traditions also show that most of these commandments were sent down during the final stage of the Holy Prophet's life at Madinah. For instance, about verse 4 the commentators state that it was sent down concerning the Bani Tamim whose deputation had arrived in Madinah and started calling out to the Holy Prophet from outside the apartments (hujurat) of his wives, and according to all biographical books on the Holy Prophet's life this deputation had visited Madinah in A. H. 9. Likewise, about verse 6 a large number of the traditions of Hadith confirm that it was sent down concerning Walid bin Uqbah whom the Holy Prophet had sent to collect the zakat from the Bani al-Mustaliq, and it is well known that Walid bin Uqabah had become a Muslim on the conquest of Makkah.
The subject matter of this Surah is to teach the Muslims the manners worthy of true believers.
In the first five verses they have been taught the manners they should observe with regard to Allah and His Messenger.
Then, they have been given the instruction that it is not right to believe in every news blindly and to act according to it, without due thought. If information is received about a person, a group or a community, it should be seen carefully whether the means of the information is reliable or not. If the means is not reliable, it should be tested and examined to see whether the news is authentic or not before taking any action on it.
Then, it has been told what attitude should the other Muslims adopt in case two groups of the Muslims fall to mutual fighting.
Then the Muslims have been exhorted to safeguard against the evils that corrupt collective life and spoil mutual relationships. Mocking and taunting each other, calling others by nicknames, creating suspicions, prying into other people's affairs and back biting are the evils which are not only sins in themselves but they also corrupt society. Allah has mentioned all these evils separately and forbidden them as unlawful.
After this, the national and racial distinctions that cause universal corruption in the world have been condemned. Nations and tribes and families pride of Ancestry and their looking down upon others as inferior to themselves and their pulling down others only for the sake of establishing their own superiority is an important factor that has filled the world with injustices and tyranny. Allah in a brief verse has cut at the root of this evil by stating that all men are descendants of the same one pair and their division into tribes and communities is only for the sake of recognition, not for boasting and pride, and there is no lawful basis of one man's superiority over the other except on the basis of moral excellence.
In conclusion, the people have been told that the real thing is not the verbal Profession of the Faith but to believe in Allah and His messenger truly, to obey them in practical life and to exert sincerely with one's self and wealth in the cause of Allah. True believers are only those who adopt this attitude. As for those who profess Islam merely orally without affirmation by the heart and then adopt an attitude as if they had done someone a favor by accepting Islam, may be counted among the Muslims in the world, may even be treated as Muslims in society, but they cannot be counted as believers in the sight of Allah.
Source: Sayyid Abul Ala Maududi - Tafhim al-Qur'an - The Meaning of the Quran