Musnad Ahmad 31:926

Waki’ narrated to us, from Ibn Abi Dhi’b, from al-Maqburi, from his father, from Abu Hurairah, that he was sitting with Marwan when a funeral passed by. Abu Sa’id passed by him and said: "Stand up, O Amir, for this one [the deceased] knew that the Prophet, peace and blessings of Allah be upon him, when he followed a funeral, would not sit down until it was placed [on the ground]."