"Say: He it is Who multiplies you in the earth and to Him you will be gathered. And they say: When will this threat be (executed), if you are truthful? Say: The knowledge is with Allah only, and I am only a plain warner. But when they see it nigh, the faces of those who disbelieve will be grieved, and it will be said: This is that which you used to call for. Say: Have you considered if Allah should destroy me and those with me -- rather He will have mercy on us yet who will protect the disbelievers from a painful chastisement?"