ذِكْرُ الْإِبَاحَةِ لِلْمَرْءِ أَنْ يُصَلِّيَ عَلَى رَاحِلَتِهِ
I saw the Messenger of Allah ﷺ praying (Nafl prayer) on a donkey's back while his face was turned towards Khaibar. (Using translation from Muslim 700e)
«رَأَيْتُ النَّبِيَّ ﷺ يُصَلِّي عَلَى حِمَارٍ وَهُوَ مُتَوَجِّهٌ إِلَى خَيْبَرَ»