وَيَسْتَعْجِلُونَكَ بِالْعَذَابِ ۚ وَلَوْلَا أَجَلٌ مُّسَمًّى لَّجَاءَهُمُ الْعَذَابُ وَلَيَأْتِيَنَّهُم بَغْتَةً وَهُمْ لَا يَشْعُرُونَ (53)
(29:53) They ask you to hasten in bringing chastisement *93 upon them. Had there not been an appointed term for it, the chastisement would have already visited them; in fact it will come down upon them all of a sudden (at its appointed time) while they will not be aware of it.
*93) That is,"They are challenging you again and again that If you are a true messenger and they are really denying the Truth, then you should not delay the torment with which you threaten them. "