﴿ فَلَمَّا رَأَوْهُ زُلْفَةًۭ سِيٓـَٔتْ وُجُوهُ ٱلَّذِينَ كَفَرُوا۟ وَقِيلَ هَٰذَا ٱلَّذِى كُنتُم بِهِۦ تَدَّعُونَ ﴾

“Yet in the end, when they shall see that [fulfilment] close at hand, the faces of those who were bent on denying the truth will be stricken with grief; and they will be told, "This it is that you were [so derisively] calling for!"”

(But when they see it) i.e. chastisement in the Fire (nigh) and it is said: with their own eyes, (the faces of those who disbelieve will be awry) due to the chastisement; and it is also said this means: the faces of the disbelievers will be burnt, (and it will be said (unto them): This) chastisement (is that for which ye used to call) in the life of the world; you used to say that it will never happen.