Fussilat 41:12

Faqadahunna sabAAa samawatinfee yawmayni waawha fee kulli sama-in amrahawazayyanna assamaa addunyabimasabeeha wahifthan thalikataqdeeru alAAazeezi alAAaleem

And He completed them as seven heavens within two days and inspired [i.e., made known] in each heaven its command. And We adorned the nearest heaven with lamps [i.e., stars, for beauty] and as protection. That is the determination of the Exalted in Might, the Knowing.

So He accomplished them as seven skies in two days, and settled in every sky its (due) thing. And We have decorated the closest sky with lamps, and protected it properly. All this is the determination of the All-Mighty, the All-Knowing.