An-Nisa 4:103

فَإِذَا قَضَيۡتُمُ ٱلصَّلَوٰةَ فَٱذۡكُرُواْ ٱللَّهَ قِيَٰمٗا وَقُعُودٗا وَعَلَىٰ جُنُوبِكُمۡۚ فَإِذَا ٱطۡمَأۡنَنتُمۡ فَأَقِيمُواْ ٱلصَّلَوٰةَۚ إِنَّ ٱلصَّلَوٰةَ كَانَتۡ عَلَى ٱلۡمُؤۡمِنِينَ كِتَٰبٗا مَّوۡقُوتٗا 103

And when you have completed the prayer, remember Allah 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