Rather, it will come to them unexpectedly and bewilder them, and they (21:40)

﴿بَلْ تَأْتِيهِم بَغْتَةً فَتَبْهَتُهُمْ فَلَا يَسْتَطِيعُونَ رَدَّهَا وَلَا هُمْ يُنظَرُونَ﴾
[ الأنبياء: 40]

21:40 Rather, it will come to them unexpectedly and bewilder them, and they will not be able to repel it, nor will they be reprieved.

This fire that they shall be punished with will come upon them suddenly, without them anticipating it.
They shall not be able to repel it, nor shall they be given respite to repent and consequently be shown mercy.

Nay, it (the Fire or the Day of Resurrection) will come upon them all of a sudden and will perplex them, and they will have no power to avert it, nor will they get respite.

phonetic Transliteration

Bal tateehim baghtatan fatabhatuhum fala yastateeAAoona raddaha wala hum yuntharoona

Abdullah Yusuf Ali - Translation

Nay, it may come to them all of a sudden and confound them: no power will they have then to avert it, nor will they (then) get respite.

Safi-ur-Rahman al-Mubarakpuri

Nay, it will come upon them all of a sudden and will perplex them, and they will have no power to avert it nor will they get respite.

Page 325 English transliteration