مسند أحمد

It was narrated from Muhammad bin `Ubaidullah, from his father, that his paternal uncle said: `Ali (رضي الله عنه) was asked: Can a man ride his sacrificial animal? He said: There is nothing wrong with it; the Prophet (ﷺ) used to pass by men who were walking and he would tell them to ride his sacrificial animails, i.e. the Prophet`s sacrificial animals. He said: And there is nothing you could follow that is better than the Sunnah of your Prophet (ﷺ).