They ask you about the hour, when will be its taking place? Say: The knowledge of it is only with my Lord; none but He shall manifest it at its time; it will be momentous in the heavens and the earth; it will not come on you but of a sudden. They ask you as if you were solicitous about it. Say: Its knowledge is only with Allah, but most people do not know.

And thus did We make (men) to get knowledge of them that they might know that Allah's promise is true and that as for the hour there is no doubt about it. When they disputed among themselves about their affair and said: Erect an edifice over them-- their Lord best knows them. Those who prevailed in their affair said: We will certainly raise a masjid over them.

And those who disbelieve say: The hour shall not come upon us. Say: Yea! by my Lord, the Knower of the unseen, it shall certainly come upon you; not the weight of an atom becomes absent from Him, in the heavens or in the earth, and neither less than that nor greater, but (all) is in a clear book

And if We make him taste mercy from Us after distress that has touched him, he would most certainly say: This is of me, and I do not think the hour will come to pass, and if I am sent back to my Lord, I shall have with Him sure good; but We will most certainly inform those who disbelieved of what they did, and We will most certainly make them taste of hard chastisement.