فَانْظُرْ كَيْفَ كَانَ عَاقِبَةُ مَكْرِهِمْ أَنَّا دَمَّرْنَاهُمْ وَقَوْمَهُمْ أَجْمَعِينَ ﴿۵۱﴾ فَتِلْكَ بُيُوتُهُمْ خَاوِيَةً بِمَا ظَلَمُوا إِنَّ فِي ذَلِكَ لَآيَةً لِقَوْمٍ يَعْلَمُونَ ﴿۵۲﴾ وَأَنْجَيْنَا الَّذِينَ آمَنُوا وَكَانُوا يَتَّقُونَ ﴿۵۳﴾

﴾51﴿ Fanzur kaifa kaana 'aaqibatu makrihim annaa dammar naahum wa qawmahum ajma'een
﴾52﴿ Fatilka buyootuhum khaa wiyatam bimaa zalamoo; inna fee zaalika la Aayatal liqaw miny-ya'lamoon
﴾53﴿ Wa anjainal lazeena aamanoo wa kaanoo yattaqoon

﴾51﴿ So see how the end of their plot was! Indeed, We destroyed them and their entire people
﴾52﴿ So these are their houses, desolate because of their wrongdoing. Indeed, in this is a sign for people who have knowledge
﴾53﴿ And We saved those who believed and used to fear Allah

[51] This explains "Makarnā"—the divine plan from Allah Most High.
“We destroyed them and their people” (دَمَّرْنَاهُمْ وَقَوْمَهُمْ)—mentioning them separately shows that the punishment of those nine individuals was distinct, and the punishment of the rest of the people was separate.
The wisdom is:
When someone plots against another, the consequence of the plot returns upon the plotter himself.
As the proverb goes: “The well-digger falls into the well he dug for his brother.” (حَفَرَ بئْرًا لأخيه فَوَقَعَ فِيهِ)
Note: This verse is expressed in a way that, with the word “fa-unẓur” (فَانْظُرْ – “So look”), indicates that the main purpose is to reflect upon the great event of the punishment of the deniers and the salvation of the believers.

[52] “Khāwiyah” (خَاوِيَةً) means empty of inhabitants or collapsed.
“Fa-tilka” (فَتِلْكَ) refers to something visible and present—indicating that the ruins of the cities of the people of Salih are still present and observable.
“A sign for people who understand” (لَآيَةً لِقَوْمٍ يَعْلَمُونَ)—this is said because the deserted ruins of that nation in the region of Madā’in Sāliḥ, near the road to Tabuk, still exist even now.
The wisdom is: Many nations have been destroyed, and their ruins remain so that later generations may take heed and learn a lesson from them.
[53] This is proof that the cause of salvation is faith and piety, and this is the great wisdom of this story—that even the righteous are in need of Allah Most High for their salvation.