Majma al-Zawaid — Hadith 13234

Muhajir, the freed slave of the family of Ziyad, narrates: Once I was riding my donkey, and because it was small my feet were nearly reaching the ground. Meanwhile the Commander of the Faithful, Sayyiduna Ali bin Abi Talib (may Allah be pleased with him), appeared in front of me; he was looking at the moon. I said: "O Commander of the Faithful, where do you intend to go?" He said: "For some business of mine." I said: "Will you not ride?" He said: "Very well." I moved back onto the rear part of the donkey and said: "O Commander of the Faithful, please ride." He said: "I will not do that. I heard the Prophet (peace and blessings be upon him) saying: 'The owner of a riding animal has more right to its front part, and the owner of bedding has more right to the prominent part of the bedding.'"
Al-Tabarani recorded it in al-Mu'jam al-Awsat. Its chain contains a narrator, Yahya bin Kathir Abu al-Nadr, and he is da'if (weak).