The Surah can be divided into the following six paragraphs.
The surah begins with the assertion that the Day of Judgement is certain to come. The Day shall evaluate a person according to his faith and deeds; it shall upgrade many a people and downgrade many of them. As a result of this assessment people shall be divided into three categories: the ashaab-ul-yameen, the ashaab-us-shimaal and the saabiqoon-ul-awwaloon.
Those nearest to the Almighty will be the saabiqoon-ul-awwaloon. The details of the gifts and favours of their Lord which they shall receive in paradise are recounted together with the qualities of the saabiqoon-ul-awwaloon which actually entitled them to these favours.
The second place shall be occupied by the ashaab-ul-yameen. A dilineation is made of the bounties and rewards which they shall be blessed with in parardise and their personal high character which made them worthy of this life of bliss.
The horrible fate of the ashaab-us-shimaal is depicted and a reference is made to a few of their grave sins which led them to this terrible punishment.
The Quraish are directly addressed and warned that they shall end up with the same fate as that of the ashaab-us-shimaal if they persist in their attitude of denying the Prophet (sws). In this regard, a reference is made to certain self-evident arguments which bear evidence to the Day of Reward and Punishment. Such is the nature of these arguments that no excuse but stubborness on their part can deny them.
An indication is made to the exalted status of the Quran and the fact that it is above and beyond the reach of Satan and his agents. The Quraish are again cautioned not to turn a deaf ear towards this sublime message and invite their doom. The fate which this Book is informing them about is a reality. Fortunate are they who will today strive to attain a place among the ashaab-ul-yameen and the saabiqoon-ul-awwaloon; those who will not do so, shall end up among the ashaab-us-shimaal and shall face a grievous penalty.
(Translated from Islahi's "Taddabur-i-Quran" ---Shehzad Saleem