"They ask you about the Hour: When will it take place? Say: The science of the Hour belongs to My Lord. Only He will reveal the term. The secret that surrounds it weighs on the inhabitants of heaven and earth. It can not surprise you otherwise than unexpectedly. [They ask you] as if you were informed! Say: Only God knows it! but most men are ignorant. Quran (7, 187).
A Bedouin questioned the Envoy of God - on him grace and peace -: "When will the Hour take place?
Assuming she is already there, what have you prepared for that moment? replied the Prophet
By God, O Messenger of God, replied the Bedouin, I have not multiplied prayers or magical works, but I love God and His Messenger. - Rejoice, you will be reunited with those whom you loved! »(Bukhâri.)