Sahih al-Bukhari 1000
Book 14: Witr Prayer · Narrated by Ibn `Umar
Arabic
حَدَّثَنَا مُوسَى بْنُ إِسْمَاعِيلَ، قَالَ حَدَّثَنَا جُوَيْرِيَةُ بْنُ أَسْمَاءَ، عَنْ نَافِعٍ، عَنِ ابْنِ عُمَرَ، قَالَ كَانَ النَّبِيُّ صلى الله عليه وسلم يُصَلِّي فِي السَّفَرِ عَلَى رَاحِلَتِهِ، حَيْثُ تَوَجَّهَتْ بِهِ، يُومِئُ إِيمَاءً، صَلاَةَ اللَّيْلِ إِلاَّ الْفَرَائِضَ، وَيُوتِرُ عَلَى رَاحِلَتِهِ.
English translation
Narrated Ibn `Umar:The Prophet (ﷺ) used to offer (Nawafil) prayers on his Rahila (mount) facing its direction by signals, but not the compulsory prayer. He also used to pray witr on his (mount) Rahila
Reference: Sahih al-Bukhari 1000, Book of Witr Prayer. English translation by Dr. Muhammad Muhsin Khan.