Whether this Surah is a Makki or a Madani is disputed. But the subject matter of the Surah and its style clearly indicate that it is not only Makki, but was revealed in the early stage of Makkan period.
An example that horses are more grateful to their owners than men are to their Rabb (Allah).
The object of this Surah is to make people realize how evil man becomes when he denies the Hereafter, or becomes heedless of it, and also to warn them that in the Hereafter not only their visible and apparent deeds, but even the secrets hidden in their hearts too will be subjected to scrutiny. For this purpose, the general chaos and confusion prevailing in Arabia: bloodshed, looting and plundering on every side; tribes subjecting other tribes to raids, no one could have peaceful sleep at night out of fear that some enemy tribe might raid his settlement early in the morning, is pointed out. Every Arab was fully conscious of this state of affairs and realized that it was wrong. Although the plundered bemoaned his miserable, helpless state and the plunderer rejoiced when the plunderer himself was plundered, he too realized how abject was the condition in which the whole nation was involved. Referring to this very state of affairs, it is said: all this is happening because the people do not know their life after death and their accountability before Allah.
Then an example of stallions (horses used in war) is given to reflect on human attitude towards Allah. Stallions to whom man provide food and water are so grateful to him that they jump into the valley of death on his command while man is ungrateful to Allah even though He has given him life, all faculties, food and other provisions. This example shows that an ungrateful person is worse than an animal. Such a person is so blinded by the love of worldly wealth that he tries to obtain it by every means, however impure and filthy it may be. He would never have behaved so had he known the time when the dead would be raised from their graves and when the intentions and motives with which they had done all sorts of deeds in the world would be exposed and brought out before everyone to see by their Lord and Sustainer (Allah) Who knows what man has done and what punishment or reward man should be awarded.