"The messenger of Allah (peace be upon him) used to pray atop his mount while traveling, facing whatever direction it was facing, and he would pray witr atop it, but he did not pray the prescribed prayers atop it ".
كَانَ رَسُولُ اللَّهِ ﷺ يُصَلِّي عَلَى الرَّاحِلَةِ قِبَلَ أَىِّ وَجْهٍ تَوَجَّهُ بِهِ وَيُوتِرُ عَلَيْهَا غَيْرَ أَنَّهُ لاَ يُصَلِّي عَلَيْهَا الْمَكْتُوبَةَ