Surah An-Nur 24:39

وَٱلَّذِينَ كَفَرُوٓا۟ أَعْمَـٰلُهُمْ كَسَرَابٍۭ بِقِيعَةٍ يَحْسَبُهُ ٱلظَّمْـَٔانُ مَآءً حَتَّىٰٓ إِذَا جَآءَهُۥ لَمْ يَجِدْهُ شَيْـًٔا وَوَجَدَ ٱللَّهَ عِندَهُۥ فَوَفَّىٰهُ حِسَابَهُۥ ۗ وَٱللَّهُ سَرِيعُ ٱلْحِسَابِ

But those who disbelieved - their deeds are like a mirage in a lowland which a thirsty one thinks is water until, when he comes to it, he finds it is nothing but finds Allāh before him, and He will pay him in full his due; and Allāh is swift in account.

Translation: Saheeh International

Tafsir

And as for those who disbelieve their works are like a mirage in a plain qī‘a is the plural of qā‘ that is to say fulāt ‘an open space’. A mirage is a kind of radiation which one might observe therein at midday during extreme heat resembling running water — which the thirsty man supposes to be water until he comes to …

Excerpt from Tafsir al-Jalalayn, commentary on 24:39, via Quran.com. The reader has the full commentary and 9 more tafsirs.