The Surah takes its name from the sentence Dhalika yaum-ut taghabun of verse 9, thereby implying that it is the Surah in which the word at taghabun has occurred.
Muqatil and Kalbi say that it was partly revealed at Makkah and partly at Madinah. Hadrat Abdullah bin Abbas and Ata bin Yasar say that vv. 1-13 were revealed at Makkah and vv. 14-18 at Madinah. But the majority of commentators regard the whole of the surah as a Madinan Revelation. Although there is no internal evidence to help determine its exact period of revelation, yet a study of its subject matter shows that it might probably have been sent down at an early stage at Madinah. That is why it partly resembles the Makkah surahs and partly the Madinan Surahs.
The theme of this surah is invitation to the Faith and obedience (to Allah) and the teaching of good morals. The sequence followed is that the first four verses are addressed to all men; verses 5-10 to those men, who do not believe in the invitation of the Qur'an; and verses 11-18 to those who accept and believe in this invitation.
In the verses addressed to all men, they have been made aware in a few brief sentences of the four fundamental truths:
First, that the universe in which they live is not Godless, but its Creator, Master and Ruler is an All Powerful God, and everything in it testifies to His being most Perfect and absolutely faultless.
Second, that the universe is not without purpose and wisdom, but its Creator has created it with truth no one should be under the delusion that it is a mock show, which began without a purpose and will come to an end without a purpose.
Third, that the excellent form that God has created you with and the choice that He has given you to choose between belief and unbelief is not a useless and meaningless activity so that it may be of no consequence whether you choose belief or unbelief. In fact, God is watching as to how you exercise your choice.
Fourth, that you have not been created irresponsible and un-answerable. You have to return ultimately to your Creator, and have to meet the Being who is aware of everything in the universe, from Whom nothing is hidden, to Whom even the innermost thoughts of the minds are known.
After stating these four fundamental truths about the Universe and Man, the address turns to the people who adopted the way of unbelief, and their attention is drawn to a phenomenon which has persisted throughout human history, namely that nation after nation has arisen and ultimately gone to its doom. Man by his intellect and reason has been explaining this phenomenon in a thousand ways, but Allah tells the real truth and declares that the fundamental causes of the destruction of the nations were only two:
First, that they refused to believe in the Messengers whom He sent for their guidance, with the result that Allah too left them to themselves, and they invented their own philosophies of life and went on groping their way from one error to another.
Second, that they also, rejected the doctrine of Hereafter, and thought this worldly life to be an end in itself, and that there was no life hereafter when they would have to render an account of their deeds before God. This corrupted their whole attitude towards life, and their impure morals and character so polluted the world that eventually the scourge of God itself had to descend and eliminate them from the scene.
After stating these two instructive truths of human history, the deniers of the message of Truth have been admonished to wake up and believe in Allah, His Messenger and the Light of Guidance that Allah has sent in the form of the Qur'an if they want to avoid the fate met by the former peoples. Besides, they have been warned that the Day shall eventually come when all the former and the latter generations will be collected at one place and the fraud and embezzlement committed by each will be exposed before all mankind. Then the fate of each man will be decided finally on the basis as to who had adopted the path of the Faith and righteousness and who had followed the way of disbelief and denial of the Truth. The first group shalt deserve eternal Paradise and the second shall be doomed to everlasting Hell.
Then, addressing those who adopt the way of the Faith, a few important instructions have been given:
First, that whatever affliction befalls a person in the world, it befalls him by Allah's leave. Whoever in this state of affliction remains steadfast to the Faith, Allah blesses his heart with guidance; otherwise although the affliction of the one who in confusion or bewilderment turns away from the path of the Faith, cannot be averted except by Allah's leave, yet he becomes involved in another, the greatest affliction of all, namely that his heart is deprived of the guidance of Allah.
Secondly, that the believer is not required to affirm the faith with the tongue only, but after the affirmation of the Faith he should practically obey Allah and His Messenger. If he turns away from obedience he would himself be responsible for his loss, for the Holy Messenger of Allah (upon whom be His peace) has become absolved from the responsibility after having delivered the message of Truth.
Thirdly, that the believer should place his trust in Allah alone and not in his own power or some other power of the world.
Fourthly, that the worldly goods and children are a great trial and temptation for the believer, for it is their love which generally distracts man from the path of faith and obedience. Therefore, the believers have to beware some of their children, and wives lest they become robbers for them on the Way of God directly or indirectly; and they should spend their wealth for the sake of God so that their self remains safe against the temptations of Satan.
Fifthly, that every man is responsible only to the extent of his power and ability. Allah does not demand that man should exert himself beyond his power and ability. However, the believer should try his best to live in fear of God as far as possible, and should see that he does not transgress the bounds set by Allah in his speech, conduct and dealings through his own negligence.
Source: Sayyid Abul Ala Maududi - Tafhim al-Qur'an - The Meaning of the Quran