Verse 12

فَقَضَىٰهُنَّ سَبْعَ سَمَـٰوَاتٍ فِى يَوْمَيْنِ وَأَوْحَىٰ فِى كُلِّ سَمَآءٍ أَمْرَهَا وَزَيَّنَّا ٱلسَّمَآءَ ٱلدُّنْيَا بِمَصَـٰبِيحَ وَحِفْظًا ذَٰلِكَ تَقْدِيرُ ٱلْعَزِيزِ ٱلْعَلِيمِ

He then completed them as seven vacua in two days, and He inspired in each vacuum its law. And We adorned the lowest vacuum with lamps, and placed therein guards. Such is the design of The Almighty, The All Knowing.