Overall meaning : Allah instructs His Prophet, Muhammad, may Allah bless him and grant him peace, to say to the unbelievers: Tell me, if Allah’s punishment befalls you (with a massive, destructive earthquake, for instance) or the Day of Judgement comes upon you, will you call any but Allah to save you from that, if you are truthful in your claim that those you call upon Allah can do any harm or good? Rather, it is Him alone that you will then invoke, whereupon He will, if He so wills, remove the affliction which caused you to call on Him, and you will forget those you worship besides Him in such times of adversity and distress.
The Almighty then states that He sent messengers to communities before Prophet Muhammad, may Allah bless him and grant him peace, but they rejected them and called them liars, and so Allah afflicted them with extreme poverty and severe hardships and diseases, so that they might humble themselves, implore Him earnestly and worship Him alone sincerely.
Yet, when Allah tested them with such adversities, they did not humbly turn to Him and beseech Him to take away the punishment; rather, their hearts hardened, and Satan made their evil deeds (unbelief, acts of disobedience and associating partners with Him), which He abhors, seem fair to them.
Then, when they deliberately neglected the warning they had received and wilfully disobeyed Allah’s commands, completely ignoring them, Allah replaced their poverty with affluence and their diseases with good health, thereby leading them step by step to their ruin; but just as they were conceitedly rejoicing in what they were given, Allah suddenly inflicted a severe punishment on them, so that they were plunged into utter despair. Thus were the wrongdoers annihilated, and none of them was to be spared. All praise belongs to Allah, the Lord of all the worlds!