فَكَذَّبُوهُ فَأَخَذَهُمْ عَذَابُ يَوْمِ ٱلظُّلَّةِ ۚ إِنَّهُۥ كَانَ عَذَابَ يَوْمٍ عَظِيمٍ
Asad Quran Translation
But they gave him the lie. And thereupon suffering overtook them on a day dark with shadows:78
and, verily, it was the suffering of an awesome day!
This may refer either to the physical darkness which often accompanies volcanic eruptions and earthquakes (which, as shown in 7:91 , overtook the people of Madyan), or to the spiritual darkness and gloom which comes in the wake of belated regrets.
Malik Quran Translation
So they disbelieved him, and the torment of the day of darkness (dark clouds carrying Allah's scourge) seized them, and indeed it was the torment of an extremely dreadful day.
Yusuf Ali Quran Translation
But they rejected him. Then the punishment of a day of overshadowing gloom seized them and that was the Penalty of a Great Day. 3220 3221
Perhaps a shower of ashes and cinders accompanying a volcanic eruption. If these people were the same as the Midianites, there was also an earthquake. See vii. 91 and n. 1063.
It must have been a terrible day of wholesale destruction-earthquake, volcanic eruption, lava, cinders and ashes and rumbling noises to frighten those whose death was not instantaneous.
Mustafa Khattab Quran Translation
So they rejected him, and ˹so˺ were overtaken by the torment of the day of the ˹deadly˺ cloud.1
That was really a torment of a tremendous day.
They were targeted by scorching heat, so they did not know where to go. Finally, a soothing cloud appeared in the sky, so they rushed to it for shade, then the cloud rained torment upon them, as they had requested.
Piktal Quran Translation
But they denied him, so there came on them the retribution of the day of gloom. Lo! it was the retribution of an awful day.
Fakaththaboohu faakhathahum AAathabu yawmi alththullati innahu kana AAathaba yawmin AAatheemin