Overall meaning : When distress afflicts man, he calls out to Us to relieve his affliction; but when We bestow upon him a favour by Our grace, he says, ‘I have been given all this by virtue of my knowledge.’ By no means! It is but a test, yet most of the unbelievers do not know that.
The same was said by the unbelievers from the nations before them, and all the worldly goods they possessed did not avail them at all when the punishment descended upon them. They suffered the terrible consequences of the evil deeds that they had committed. The wrongdoers among the Quraysh unbelievers will also suffer the dire consequences of their evil deeds. They will never frustrate Our purpose: We are capable of inflicting punishment on them.
Do they not know that Allah gives abundant sustenance to whomever He wills and gives it sparingly to whomever He pleases? Surely in this there are signs for true believers.