“We sent (or unleashed) against them a single loud cry (or explosion), so, they became like the dry crumbled twig fragments of an [animal] pen (or used by the person who makes the pen/enclosure)”.
Central sense: reaching the utmost limit; penetrating from the depths; rising or expanding with power.
Although “single” is implicit in صَيْحَةً, “one” appears for emphasis or as a response to the prior statement of Thamud regarding following just “one single” person.
هَشِيمِ: dry, weak, crumbled branches, twigs, straw, thorns — crushed debris of dry vegetation.
A sudden, overwhelming, terminal event — power erupting decisively.
Reduced to frail debris — imagery of هَشِيمِ.
Only good enough to build a simple sheep pen — الْمُحْتَظِرِ.
The addition of “one” reinforces the singular, decisive nature of the event — and can be read as responding to Thamud’s stance about following just “one single” person. The result is a vivid image of absolute reduction.
Great civilisation, buildings, and might do not prove true progression. Complete destruction indicates they no longer held any value in Allah’s sight.
They came as a result of peoples and nations rejecting Prophets and miracles.
It is incorrect to compare all calamities — natural disasters, plagues, wars — with the destruction of those nations and view them as punishments sent by Allah. These should be viewed as trials and tests from Allah and not punishments from Allah.
A people of might were reduced to the weakest materials — imagery that underlines the finality of the outcome.
إِنَّا أَرْسَلْنَا عَلَيْهِمْ صَيْحَةً وَاحِدَةً فَكَانُوا كَهَشِيمِ الْمُحْتَظِرِ
Single decisive act — single emphasis — complete reduction. The wording compresses cause, force, and result into a stark image.