Musnad Abu Ya'la al-Mawsili 3:13

Abu Khaythama narrated to us, Yazid bin Harun narrated to us, Yahya bin Sa'id and Muhammad bin 'Amr informed us, from Waqid bin 'Amr bin Sa'd bin Mu'adh, who said: I went out for a funeral, so I stood waiting for it to be placed down so that I could sit. Nafi' bin Jubayr was near me, and when it was placed down, I sat beside him. He said, "It is as if you waited for this funeral to be placed down so that you could sit?" I said, "Yes, because of a hadith that reached me from Abu Sa'id." He said, "Mas'ud narrated to me that he heard 'Ali say: The Messenger of Allah (peace and blessings of Allah be upon him) stood for a funeral, then he sat and commanded us to sit."