This Sūra is close in date to the last: it is generally referred to the early Medīna period, though it may possibly be of the late Meccan period.
It refers to the tremendous convulsion and uprooting which will take place when the present order of the world is dissolved and the new spiritual world of Justice and Truth takes its place. The symbol used is that of an earthquake which will shake our present material and phenomenal world to its very foundations. The mystic words in which the earthquake is described are remarkable for both power and graphic aptness. With that shaking all hidden mysteries will be brought to light.

C. 279 | [99:1-8] The Hour of Judgment must needs be heralded by a mighty Convulsion: the Earth will give up her secrets and tell her tale of all man’s doings; men will march in companies and clearly see the inwardness of all their Deeds: not an atom of Good or Evil done, but will be shown in the final Account of men convinced.