Anas Radiyallahu 'Anhu reports:
"Rasulullah Sallallahu 'Alayhi Wasallam visited the sick, attended funerals, rode on donkeys, accepted the invitations of slaves. On the day of the battle of Banu Qurayzah, he rode on a donkey, the reigns of which were made of date palm leaves. On it was also a saddle made of date palm leaves". (ID)
English reference (ID): Book 46, Hadith 315 (ID)
Arabic reference (ID): Book 47, Hadith 332 (ID)