Overall meaning : Allah Almighty states that the unbelievers, annoyed by what the messengers said to them, threatened them, saying, ‘We will surely expel you from our land unless you return to our religion.’ So Allah revealed to His messengers, ‘We will surely destroy the wrongdoers and make you and your followers dwell in their land after their destruction. This is My promise to those who fear standing before Me on the Day of Judgement and fear My punishment by doing what I command and avoid what I forbid.’
The messengers then prayed to their Lord for help and asked Him to destroy their enemies and give them victory over them, and so every arrogant tyrant who obstinately rejected the truth was doomed to destruction, with Hell awaiting him to suffer its punishment in the hereafter and to be made to drink the blood and pus flowing from the bodies of the dwellers of Hell. He will sip it against his will, due to his extreme thirst, and he will be hardly able to swallow it because of its fetid odour, intense heat and bitterness. Death, with all its severity and agony, will come to him from every organ and place of his body and from every side, but he will not die and thus be relieved. Awaiting him, after such punishment, will be yet another harsh torment.
Allah then strikes out a parable to depict the unbelievers’ good actions, saying: The good deeds that the unbelievers do in this life are like ashes which the wind blows about fiercely and scatters on a stormy day such that nothing remains of it. Just as the fierce wind violently scatters the ashes, so, too, unbelief destroys the reward for their good deeds such that they will find nothing with Allah whatsoever to benefit them in the life to come. That is truly the farthest one can stray from the right way.