Tafsir of Ash-Shu`ara' 26:189

{فَأَخَذَهُمْ} God seized them with the likes of what they had proposed—the punishment of the "Shadow" (al-ẓulla). If they meant by "the sky" the clouds, then it was that; if they meant a canopy, then He diverted them from their own proposal.

It is narrated that the wind was withheld from them for seven days, and the heat (al-wamd) was unleashed upon them. It choked their breath, and neither shade, nor water, nor shelter availed them. They were forced to flee into the wilderness, where a cloud shaded them, and they found in it coolness and a breeze. They gathered beneath it, and it rained fire upon them, burning them.

It is also narrated that Shuʿayb was sent to two nations: the people of Madyan and the people of al-Aykah. Madyan was destroyed by the cry of Gabriel, and the people of al-Aykah by the punishment of the Day of the Shadow.

If you ask: Why was the repetition at the beginning and end of every story in this Surah repeated as it was?

I say: Each story is like a separate revelation in itself, containing as much admonition as the others. Each one has a right to be opened and concluded in the same manner as its counterpart.

Furthermore, repetition serves to establish meanings within the soul and fix them in the hearts. Do you not see that there is no way to memorize knowledge except by repeating what one wishes to retain? The more it is repeated, the more firmly it settles in the heart, the more deeply it is understood, the more fixed it is in memory, and the further it is from forgetfulness.

Moreover, these stories were addressed to ears that were deaf to listening to the Truth, and hearts that were veiled from contemplating it. Thus, they were inundated with preaching and reminding, and revisited with repetition and reiteration, in the hope that it might open an ear, awaken a mind, polish an intellect that had long gone unpolished, or clear an understanding covered by the accumulation of rust.

{وَإِنَّهُ لَتَنزِيلُ رَبِّ الْعَالَمِينَ * نَزَلَ بِهِ الرُّوحُ الْأَمِينُ * عَلَىٰ قَلْبِكَ لِتَكُونَ مِنَ الْمُنذِرِينَ * بِلِسَانٍ عَرَبِيٍّ مُّبِينٍ * وَإِنَّهُ لَفِي زُبُرِ الْأَوَّلِينَ}