Hadith 6:458
Waki’ narrated to us, from Thawr, from Rashid ibn Sa’d, that Thawban saw a man riding in a funeral procession. He took hold of the bridle of his mount and began to restrain it, and said: "You ride while the servants of Allah are walking?"
حدثنا وكيع عن ثور عن راشد بن سعد عن ثوبان أنه رأى رجلا راكبا في جنازة فأخذ بلجام دابته فجعل يكبحها وقال تركب وعباد الله يمشون