Sunan an-Nasa'i, Book 20, Hadith 91 (In-Book) ⓘ
It was narrated that Sa'eed bin Yasir said: "Ibn Umar said to me that the Messenger of Allah used to pray witr on a camel."
أَخْبَرَنَا قُتَيْبَةُ، قَالَ حَدَّثَنَا مَالِكٌ، عَنْ أَبِي بَكْرِ بْنِ عُمَرَ بْنِ عَبْدِ الرَّحْمَنِ بْنِ عَبْدِ اللَّهِ بْنِ عُمَرَ بْنِ الْخَطَّابِ، عَنْ سَعِيدِ بْنِ يَسَارٍ، قَالَ قَالَ لِي ابْنُ عُمَرَ أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم كَانَ يُوتِرُ عَلَى الْبَعِيرِ .
also referenced under: Hadith 1688 (Reference) & Volume 2, Book 20, Hadith 1689 (DarusSalam)