When We show mercy to mankind after some calamity had afflicted them, they begin to plot against Our verses.! Tell them: “Allah is more Swift in plotting than you; indeed Our angels are recording all the plots you make.”
Meaning:-
Calamity: an event causing great and often sudden damage or distress; a disaster.
Afflict: (of a problem or illness) cause pain or suffering to; affect or trouble, burden.
Swift: happening quickly or promptly.