Translation of the verse 21 from Surah An-Naba’ : Number of verses 40 - - page 582 - Part 30.
Truly, Hell is a place of ambush,
Indeed, Hell has been lying in wait
(78:21) Surely the Hell is an ambush, *14
*14) "An ambush": a place contrived to entrap game by surprise. Hell has been described as an ambush, because the rebels of God are fearless of it and are enjoying life thinking that the world is a haven of bliss for them. They do not know that Hell is lying in ambush for them, which will trap them suddenly and keep them trapped.
Source : An-Naba’ Verse 21: Indeed, Hell has been lying in wait