The Book of Qiyam Al-Lail (The Night Prayer) and Voluntary Prayers During the Day
20/33. Chapter:
Witr on one's mount
Sunan an-Nasai
أَخْبَرَنَا عُبَيْدُ اللَّهِ بْنُ سَعِيدٍ، قَالَ حَدَّثَنَا يَحْيَى بْنُ سَعِيدٍ، عَنْ عُبَيْدِ اللَّهِ بْنِ الأَخْنَسِ، عَنْ نَافِعٍ، عَنِ ابْنِ عُمَرَ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم كَانَ يُوتِرُ عَلَى الرَّاحِلَةِ .
It was narrated from Ibn Umar that: The Messenger of Allah (ﷺ) used to pray witr on his mount.
Reference : Sunan an-Nasa'i 1686In-book reference : Book 20, Hadith 89English translation : Vol. 2, Book 20, Hadith 1687