Musnad Ahmad 31:447

Wahb ibn Jarir narrated to us, Shu'bah narrated to us, from 'Abdullah ibn Abi al-Safar, from al-Sha'bi, from Abu Sa'id al-Khudri, who said: A funeral procession passed by Marwan, and he did not stand up. Abu Sa'id said: "The Messenger of Allah (peace and blessings of Allah be upon him) had a funeral procession pass by him, and he stood up." He said: So Marwan stood up.