Sixth sign of divine omnipotence
Existence of the sky and earth is by the command of Allah. When He will command the breakup of this system, this strong arrangement, which is working since thousands of years perfectly without a slight depreciation, will end up in no time. Then by the command of Allah all the dead will assemble in the plain for reckoning.
The sixth sign of divine omnipotence is in fact the sum and substance of the previous five signs, and they were in fact revealed to explain and elaborate this verse. The subject of this verse continues in the next few verses.