Ubaidullah bin Mua'dh عبيد الله بن معاذ بن معاذ بن نصر · Funerals (Kitab Al-Jana'iz)

An animal was brought to the Messenger of Allah (ﷺ) while he was going with a funeral. He refused to ride on it. When the funeral was away, the animal was brought to him and he rode on it. He was asked about it. He said: The angels were on their feet. I was not to ride while they were walking. When they went away, I rode.

That 'Abd al-Rahman b. 'Awf alighted in the grave of the Prophet (ﷺ). He said: I still seem to see the four of them.