When they said: 'Will we really be bones?' it was said to them: 'Be stones or iron.' His saying 'be' responds to their saying 'we were,' as if it were said: 'Be stones or iron and do not be bones.' For He is capable of reviving you. The meaning is that you find it hard to believe that Allah can renew your creation and return it to the state of life and the moisture of the living after you were dry bones. Although bones are part of the living, they are indeed the backbone of its creation upon which the rest is built. It is not strange for Allah to return them by His power to their original state. However, if you were the farthest thing from life and the moisture of the living, and of the kind from which humans are made - that is, if you were dry stones or iron, despite their nature of hardness and toughness - He would still be capable of returning you to life or creating something that is beyond what you can imagine, meaning something that seems to you too great to accept life and too immense in your opinion for the Creator to revive it, yet He revives it. It was said: what is too great in their hearts is death. It was also said: the heavens and the earth. 'So they will shake it' means they will move it towards you in astonishment and mockery.