Qur'an 4:103 · An-Nisaa

فَإِذَا قَضَيْتُمُ ٱلصَّلَوٰةَ فَٱذْكُرُوا۟ ٱللَّهَ قِيَٰمًۭا وَقُعُودًۭا وَعَلَىٰ جُنُوبِكُمْ ۚ فَإِذَا ٱطْمَأْنَنتُمْ فَأَقِيمُوا۟ ٱلصَّلَوٰةَ ۚ إِنَّ ٱلصَّلَوٰةَ كَانَتْ عَلَى ٱلْمُؤْمِنِينَ كِتَٰبًۭا مَّوْقُوتًۭا

(103) And when you have completed the prayer, remember Allāh standing, sitting, or [lying] on your sides. But when you become secure, re-establish [regular] prayer. Indeed, prayer has been decreed upon the believers a decree of specified times.