Warning against dreadful end of those committing three obnoxious sins.
This Surah is Makki and has 9 verses.
Woe to every backbiter, derider  who accumulates wealth and counts it.  He thinks that his wealth has made him eternal.  Never! He will certainly be thrown into the Crusher.  And what may let you know what the Crusher is?  It is Allah's kindled fire,  that will peep into the hearts.  It will be closed on them,  in outstretched columns. 
This Surah warns of the severe punishment on three grave sins, and then highlights the nature of that severe punishment. The three sins are backbiting, deriding and selfish hoarding of wealth. The word hamz
are used in several senses. Most commentators agree that the word hamz
, from which is derived the word humqzah
, means to 'backbite', that is, to speak ill of a person behind his back. The word lamz
, from which is derived the word lumazah
, means 'to slander' or 'to deride', that is, to speak ill of a person to his face. Both these sins are morally and socially obnoxious and deadly. The Quran and the Sunnah have sounded a stern warning against these sins. However, 'backbiting' is from one perspective, worse than 'slander'. 'Backbiting' is worse because the ill of a person is spoken behind his back; the victim is not present to defend himself and put an end to it; thus the sin continues to be committed to a greater and increasing degree. 'Slander' on the other hand though an obnoxious sin in itself, is relatively less in degree than backbiting, because the victim is present to defend himself and put an end to face-to-face insulting or fault-finding with him. From another perspective 'slander' is worse than 'backbiting', because to speak ill of a person to his face is tantamount to insulting him and denigrating him. This is morally and socially more harmful and hurting, and therefore its punishment is more dreadful. According to a Hadith, the Holy Prophet (saw) has said,
"The worst servants of Allah are those who speak ill of someone, creating enmity between friends and finding fault with innocent people"
The third evil quality denounced severely in this Surah is greed, that is, selfish hoarding of wealth, against which is the stern warning of the dreadful end of those who have passion for wordly riches. This verse, however, refers to the love of, and passion for, wealth which is accumulated and counted over and over again. Other verses and Ahadith bear testimony to the fact that amassing of wealth in principle is not prohibited or sinful. Therefore, verse  must be interpreted in light of those verses and traditions. This verse purports to say that anyone who accumulates wealth and does not pay his obligatory dues or has greed for wealth that leads him into pride and arrogance, or has love of wealth that engrosses him in the hoarding of wealth so profoundly that he forgets his religious obligations, his practice is condemned in the strongest terms, and a person attaining such profound love, greed and passion for material riches will suffer eternal perdition as described in the verses that follow.
Verse [104:7] (that will peep into their hearts). In other words, the fire of Hell will reach their hearts. The basic property of fire is to burn every particle of the things that fall into it. When people are put into the Hell-Fire, it will devour every limb and organ of the body until it reaches their heart, but the person will not die. This characteristic of the Hell-Fire is especially highlighted in the verse because the fire of this world kills the person even before reaching the heart. The fire of the Hell, on the other hand, will reach the heart in the state of life, and man will experience the torture of the burning of the heart while alive.