قَدْ أَفْلَحَ مَن زَكَّاهَا ﴿9﴾ وَقَدْ خَابَ مَن دَسَّاهَا ﴿10﴾ (success is really attained by him who purifies it, and failure is really suffered by him who pollutes it....91:10). This is the subject of the seven oaths. The primitive meaning of tazkiyah is 'inner cleanliness', signifying 'he who obeyed Allah and purified his inner and outer selves.' Verse [ 10] signifies 'he who caused his soul to sink in the swamp of sins will be deprived'. The word dassa is derived from the basic word dass' which denotes 'to bury in the ground' as for instance it occurs elsewhere in the Qur'an, thus:

أَمْ يَدُسُّهُ فِي التُّرَ‌ابِ

...or put it away into the dust? [ 16:59] '

Some of the commentators have analysed that the pronouns of zakka 'He purified' and dassa 'He caused to pollute' as referring to 'Allah', signifying that 'he is successful indeed whose soul Allah has purified and he has failed whose soul Allah pollutes '. This verse has divided the entire mankind into two groups: [ 1] successful; and [ 2] unsuccessful. An example of the second group has been cited to show how it rejected the message of Allah and consequently how Allah destroyed them. Such a group will receive severe punishment in the Hereafter. Sometimes, however, an installment of punishment is meted out to them in this world as in the case of Thamud. Their story is recounted fully in Surah A` raf [ S.7:73-79; S.11:61-68; S. 26:141-159; S.27:45-53; S..41:17-18; S.54:23-32; and S. 69:4-5]. Here a brief reference is made to that story and their punishment.