﴿ إِنَّآ أَرْسَلْنَا عَلَيْهِمْ رِيحًۭا صَرْصَرًۭا فِى يَوْمِ نَحْسٍۢ مُّسْتَمِرٍّۢ ﴾

“Behold, We let loose upon them a raging storm wind on a day of bitter misfortune:”

Indeed We unleashed upon them a clamorous wind intensely noisy on a day of prolonged ill fortune nahsin mustamirr means either one of continuous ill fortune or one of severe ill fortune — and this was the last Wednesday of the month —