When the Prophet ﷺ prayed the dawn prayer, he sat cross-legged where he was till the sun had come well up.  

كَانَ النَّبِيُّ ﷺ إِذَا صَلَّى الْفَجْرَ تَرَبَّعَ فِي مَجْلِسِهِ حَتَّى تَطْلُعَ الشَّمْسُ حَسْنَاءَ