And We have already destroyed what surrounds you of [those] cities, and We have diversified the signs [or verses] that perhaps they might return [from disbelief].
(We also gave them hearing, vision, and hearts. But their hearing, vision, and hearts availed them nothing when they used to deny Allah's signs, and they were completely encircled by that which they used to ridicule!) meaning, they were encircled by the torment and exemplary punishment that they denied and whose occurrence they doubted. This means, you listeners must beware of being like them lest a punishment similar to theirs strikes you in this life and the Hereafter. Allah then says,
{ 1} The reference here is to the towns of Thamud and the people of Sayyidna Lut (علیہ السلام) that were in the way of the people of Arabia while they travelled to Syria. The people of ` Ad were in Yemen, towards South from Makkah, while the towns of Thamud and those of Sayyidna Lut (علیہ السلام) were towards North, hence the words, "around you"
Commentary
These verses are to remind the infidels of the severe punishments faced by earlier people who rejected the messengers sent to them. Special reference is made to ` Ad, the people of Sayyidna Hud (علیہ السلام) who has been described as their 'brother', firstly because he belonged to their tribe, and secondly because he was their well-wisher as a brother. Since this nation lived in valleys surrounded by long, curved sand dunes, called in Arabic Ahqaf , special reference is made to these dunes, so that one could find out their places, if he so wishes when traveling to their localities. It is mentioned in verse 22 that they themselves demanded Allah's punishment to be brought upon them. Then verse 24 states that the punishment was sent to them in the form of a cloud that appeared to be benign, and therefore they were happy to see it in the hope that it would bring rain to them, but in fact it contained the divine punishment in the form of a violent wind that destroyed everything, leaving nothing except their empty homes that remained as a sign for those who might learn a lesson. The detailed account of the story of ` Ad and Thamud has already been given in Surah Hud (11:50) for which volume 4, page 643 of this book may be consulted. Mention of these events in these verses is in the form of a brief reference, and in verse 26 the infidels of Makkah are reminded that those nations were much more powerful and well-established than the people of Makkah. Still, their power and strength was of no use to them against Allah's punishment. Moreover, verse 28 points out that the false gods believed by them to be their patrons could not save them from the torment they faced, because they were coined only by their false imagination, having no real existence at all.
The people of Ad mistook the clouds of destruction for rain clouds. They understood the reality only when the raging winds entered their townships and reduced them to ruins. Man is so reckless that he does not accept the Truth even when on the brink of disaster. He accepts it only after the opportunity to repent has been taken away from him.
Uthmani text of the Madinah mushaf (King Fahd Complex). Translation: Saheeh International. Tafsir via Quran.com.