"The Messenger of Allah ﷺ used to pray voluntary prayers (Usabbih) while riding his mount, facing whatever direction it was facing, and he would pray Witr likewise, but he would not offer the prescribed prayers on it."  

كَانَ رَسُولُ اللَّهِ ﷺ يُسَبِّحُ عَلَى الرَّاحِلَةِ قِبَلَ أَىِّ وَجْهٍ تَتَوَجَّهُ وَيُوتِرُ عَلَيْهَا غَيْرَ أَنَّهُ لاَ يُصَلِّي عَلَيْهَا الْمَكْتُوبَةَ  

"The Messenger of Allah ﷺ used to pray while on his animal when he was coming back from Makkah to Madinah. Concerning this, the verse was revealed: So wherever you turn (yourselves or your faces) there is the Face of Allah.'" [1] [1] Al-Baqarah 2:115.  

كَانَ رَسُولُ اللَّهِ ﷺ يُصَلِّي عَلَى دَابَّتِهِ وَهُوَ مُقْبِلٌ مِنْ مَكَّةَ إِلَى الْمَدِينَةِ وَفِيهِ أُنْزِلَتْ { فَأَيْنَمَا تُوَلُّوا فَثَمَّ وَجْهُ اللَّهِ }  

"The Messenger of Allah ﷺ used to pray on his mount while on a journey, no matter what direction it was facing." Malik said: "Abdullah bin Dinar said: 'And Ibn 'Umar used to do likewise.'"  

كَانَ رَسُولُ اللَّهِ ﷺ يُصَلِّي عَلَى رَاحِلَتِهِ فِي السَّفَرِ حَيْثُمَا تَوَجَّهَتْ بِهِ قَالَ مَالِكٌ قَالَ عَبْدُ اللَّهِ بْنُ دِينَارٍ وَكَانَ ابْنُ عُمَرَ يَفْعَلُ ذَلِكَ