A woman named Azzah, who was one of the early women, narrated: Sayyiduna Abu Bakr addressed us in a sermon and said: "Do not pray on bardha'ahs (a pad placed on the back of a mule or donkey, as a saddle is placed on the back of a horse)!"
Imam al-Tabarani recorded it in al-Mu'jam al-Kabir, and its narrators are thiqat (trustworthy) if Azzah was a Companion, which is what appears from the statement of Abu Hazim.
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الصلاة / 2983