وَحَدَّثَنِي عَنْ مَالِكٍ، عَنْ عَمْرِو بْنِ يَحْيَى الْمَازِنِيِّ، عَنْ أَبِي الْحُبَابِ، سَعِيدِ بْنِ يَسَارٍ عَنْ عَبْدِ اللَّهِ بْنِ عُمَرَ، أَنَّهُ قَالَ رَأَيْتُ رَسُولَ اللَّهِ صلى الله عليه وسلم يُصَلِّي وَهُوَ عَلَى حِمَارٍ وَهُوَ مُتَوَجِّهٌ إِلَى خَيْبَرَ ‏.‏

Yahya related to me from Malik from Amr ibn Yahya al-Mazini fromAbu'l-Hubab Said ibn Yasar that Abdullah ibn Umar said, "I saw theMessenger of Allah, may Allah bless him and grant him peace, prayingon a donkey while heading towards Khaybar." Translation Not Available

Book Ref: Muwatta Imam Malik Book 9 Hadith 356
Web Ref:  Muwatta Imam Malik Book 9 Hadith 27