Surah Ash-Shu'ara — Ayah 189 (26:189)
فَكَذَّبُوهُ فَأَخَذَهُمۡ عَذَابُ يَوۡمِ ٱلظُّلَّةِۚ إِنَّهُۥ كَانَ عَذَابَ يَوۡمٍ عَظِيمٍ ١٨٩
English translation (Saheeh International)
And they denied him, so the punishment of the day of the black cloud seized them. Indeed, it was the punishment of a terrible day.
Brief commentary
They continued rejecting him and so a grave punishment afflicted them by way of a cloud appearing after a severely hot day. It rained a fire upon them that burned them. The day they were destroyed was an extremely horrific day.