It wasnarrated that Isma'il bin Abu Khalid said:
"I saw Abu Kahil,andhe was a Companions, and my brother narrated to me that he said:'Isaw the Prophet (ﷺ) delivering the sermon atop his she-camel, andan Ethiopian was holding onto its reins.'"
English reference: Vol. 1, Book 5, Hadith 1284
Arabic reference: Book 5, Hadith 1343