Sahih al-Bukhari 1099

Arabic

حَدَّثَنَا مُعَاذُ بْنُ فَضَالَةَ، قَالَ حَدَّثَنَا هِشَامٌ، عَنْ يَحْيَى، عَنْ مُحَمَّدِ بْنِ عَبْدِ الرَّحْمَنِ بْنِ ثَوْبَانَ، قَالَ حَدَّثَنِي جَابِرُ بْنُ عَبْدِ اللَّهِ، أَنَّ النَّبِيَّ صلى الله عليه وسلم كَانَ يُصَلِّي عَلَى رَاحِلَتِهِ نَحْوَ الْمَشْرِقِ فَإِذَا أَرَادَ أَنْ يُصَلِّيَ الْمَكْتُوبَةَ نَزَلَ فَاسْتَقْبَلَ الْقِبْلَةَ‏.‏

English translation

Narrated Jabir bin `Abdullah:The Prophet (ﷺ) used to pray (the Nawafil) on his Mount facing east and whenever he wanted to offer the compulsory prayer, he used to dismount and face the Qibla

Reference: Sahih al-Bukhari 1099, Book of Shortening the Prayers (At-Taqseer). English translation by Dr. Muhammad Muhsin Khan.