Allah the Exalted threatens those who defy His commands, deny His Messengers and contradict His legislation, by informing them of the end that earlier nations met who did the same,

﴿وَكَأِيِّن مِّن قَرْيَةٍ عَتَتْ عَنْ أَمْرِ رَبِّهَا وَرُسُلِهِ﴾

(And many a town revolted against the command of its Lord and His Messengers;) meaning, they rebelled, rejected and arrogantly refused to obey Allah and they would not follow His Messengers,

﴿فَحَاسَبْنَـهَا حِسَاباً شَدِيداً وَعَذَّبْنَـهَا عَذَاباً نُّكْراً﴾

(and We called it to a severe account, and We shall punish it with a horrible torment.) meaning, horrendous and terrifying,

﴿فَذَاقَتْ وَبَالَ أَمْرِهَا﴾

(So it tasted the evil result of its affair,) meaning, they tasted the evil consequences of defiance and they regretted their actions when regret does not avail,

﴿وَكَانَ عَـقِبَةُ أَمْرِهَا خُسْراًأَعَدَّ اللَّهُ لَهُمْ عَذَاباً شَدِيداً﴾

(and the consequence of its affair was loss. And Allah has prepared for them a severe torment.) means, in the Hereafter, added to the torment that was sent down on them in this life. Allah the Exalted said, after mentioning what happened to the disbelieving nations,

﴿فَاتَّقُواْ اللَّهَ يأُوْلِى الأَلْبَـبِ﴾

(So have Taqwa of Allah, O men of understanding,) meaning, `O you who have sound understanding, do not be like them because if you do, you will suffer what they suffered, O people of comprehension,'

﴿الَّذِينَ ءَامَنُواْ﴾

(who believe) meaning, in Allah and His Messengers,

﴿قَدْ أَنزَلَ اللَّهُ إِلَيْكُمْ ذِكْراً﴾

(Allah has indeed sent down to you a Reminder.) meaning, this Qur'an. Allah also said,

﴿إِنَّا نَحْنُ نَزَّلْنَا الذِّكْرَ وَإِنَّا لَهُ لَحَـفِظُونَ ﴾

(Verily, We, it is We Who have sent down the Dhikr and surely, We will preserve it.) (15:9)