Surah Al-Hadid, Verse 6

يُولِجُ ٱلَّيۡلَ فِي ٱلنَّهَارِ وَيُولِجُ ٱلنَّهَارَ فِي ٱلَّيۡلِۚ وَهُوَ عَلِيمُۢ بِذَاتِ ٱلصُّدُورِ٦

yūliju al-layla fī l-nahāri wayūliju l-nahāra fī al-layli wahuwa ʿalīmun bidhāti l-ṣudūri

He causes the night to enter the day and causes the day to enter the night, and He is Knowing of that within the breasts.