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Had there come to them a Qur'aan which could move the mountains or could tear up the earth or could cause the dead to speak - (they would still not have accepted it!) - nay, but every deed is within Allah's means! Did it not disappoint the believers that if Allah willed, He could have guided all mankind? The heretics will remain forever under the threat of (impending) disaster, or their dwellings surrounded by it until the promise of Allah came to pass! And verily Allah's promise never fails! (R)
 

(The verse addresses the believers of Mecca who were trapped in the grip of intolerable atrocities by their adversaries and used to say that, if it took a few miracles to convince them and put out the flames of reprisals raging in their land, why not give them that?

Even if the Qur'aan satisfied all their demands, the disbelievers of Mecca would never have been blessed with faith because faith does not grow on trees; it is not sold in market precincts; it is not delivered by postmen nor advertised in TV commercials; it is a spark that is ignited by Allah to set alight the torch of belief; it is a desire born inside our hearts without our having any control over it; an inclination that comes from within and not from without; a state of surrender induced by Allah which lasts forever; a flame that burns on the fuel of dedication and resolve! If Allah performed miracles to satisfy every doubter, there would be no end to them. He might just as well have made mankind belong to one single creed and take away from them the discretion to choose between good and evil, between right and wrong, between truth and falsehood, between heaven and hell. There would have been no need for guidance, no such thing as a Day of Judgement, no Scales of Justice, no rewards and requitals and no Reckoning! But that was not how Allah has envisaged mankind to be. He gave them this discretion to choose and then take responsibility for their decisions in the same way He had given to our first parents Adam and Eve and then forced upon them the consequences of their choice which resulted in Advent, in our coming into being and in treading the path which they had once walked!

Having answered their question and cleared their doubts, their concerns are put to ease by unequivocally asserting that the threat of disaster imposed upon the disbelievers would never be relaxed; the afflictions dealt to them in retaliation for their misdeeds will never end; the droughts will carry on coming and taking their toll; battles will go on raging and spilling their blood; ordeal upon ordeal will come their way and plunge them into turmoil until the promise of Allah comes to pass, - a promise that can nether be broken nor changed.

Many commentators contend that this irretractable and irreversible promise did come to pass with the fall of Mecca to the Muslims and the subsequent spread of Islam through the length and breadth of Arabia, not to mention the rest of the world).