﴿ وَيَسْتَعْجِلُونَكَ بِٱلْعَذَابِ ۚ وَلَوْلَآ أَجَلٌۭ مُّسَمًّۭى لَّجَآءَهُمُ ٱلْعَذَابُ وَلَيَأْتِيَنَّهُم بَغْتَةًۭ وَهُمْ لَا يَشْعُرُونَ ﴾

“Now they challenge thee to hasten the coming upon them of [God’s] chastisement: and indeed, had not a term been set [for it by God], that suffering would already have come upon them! But indeed, it will most certainly come upon them of a sudden, and they will be taken unawares.”

And they ask you to hasten the chastisement. Yet were it not for an appointed term for this chastisement the chastisement would have come upon them before long but it shall assuredly come upon them suddenly while they are unaware of the time of its coming.