A WHIFF OF WHAT IS TO COME: 21: 46
And if a breath of thy Lord’s punishment were to touch them, they assuredly would say: Alas for us! Lo! we were wrong-doers. (46)
TAFSEER BY DR. FARHAT HASHMI (translated):
If even a whiff of what is to come as Punishment of their mistaken behavior they would say that we truly are in the wrong, but right now they are justifying their actions and are adamantly set on their wrong paths.
Allah Subhanawataala in His infinite mercy is warning us through His message and Messengers and is not even sending a whiff of the Punishment for even a slight whiff of it would be so severe that humans would reel from it irreversibly.