Surah Fusilat (The Verses Prefectly Explained), Verse 12

فَقَضٰىهُنَّ سَبْعَ سَمٰوَاتٍ فِیْ یَوْمَیْنِ وَاَوْحٰی فِیْ كُلِّ سَمَآءٍ اَمْرَهَا وَزَیَّنَّا السَّمَآءَ الدُّنْیَا بِمَصَابِیْحَ وَحِفْظًا ذٰلِكَ تَقْدِیْرُ الْعَزِیْزِ الْعَلِیْمِ ۟

Faqadaahunna sab'a samaawaatin fee yawmaini wa awhaa fee kulli samaaa'in amarahaa; wa zaiyannassa maaa'ad dunyaa bimasaabeeha wa hifzaa; zaalika taqdeerul 'Azeezil 'Aleem

“So He completed them as seven firmaments in two Days, and He assigned to each heaven its duty and command. And We adorned the lower heaven with lights, and (provided it) with guard. Such is the Decree of (Him) the Exalted in Might, Full of Knowledge.”

Quran 41:12 (Yusuf Ali Translation)