The sura begins with the imagery of raiders on horseback, who come to take what is not theirs rightfully. The Quran, whose eternal message takes the form of imagery in the day and tongue of the Prophet Muhammad, gives a picture of greedy men that would be quite familiar to the Arab peoples of his day: that of the invading army in search of booty. It can be understood even now that such a hoard is an ideal example of worldliness and shirk - in Islam, the great sins against God. The image is of people who are willing to hurt their fellow man over objects and lust.
Other scholars have also said that the beginning of this surah refers to how horses behave their masters, yet us, the mankind continues to disobey our master, Allah, and so, therefore horses are better than man.
The Qur'an continues, that mankind is evidence against himself of these sins. On the Last Day, "when that which is in the tombs is overthrown and that which is in the breasts in brought out," people will be judged accordingly by what their hearts intended in life. The Qur'an concludes this sura with the reminder that as men are fully aware of what they are doing and why, God is even more aware - what is hidden in men's hearts is known to God.
The sura can be translated into English as: By the snorting coursers, (1) Striking sparks of fire (2) And scouring to the raid at dawn, (3) Then, therewith, with their trail of dust, (4) Cleaving, as one, the centre (of the foe), (5) Lo! man is an ingrate unto his Lord (6) And lo! he is a witness unto that; (7) And lo! in the love of wealth he is violent. (8) Knoweth he not that, when the contents of the graves are poured forth (9) And the secrets of the breasts are made known, (10) On that day will their Lord be perfectly informed concerning them. (11)