Musnad Ahmad 5:601

Muhammad ibn Ja‘far narrated to us, Shu‘bah narrated to us, and Hajjaj narrated to us, Shu‘bah informed us, he said: I heard Muhammad ibn al-Munkadir, he said: I heard Mas‘ud ibn al-Hakam, he said: I heard ‘Ali. Hajjaj said: He said: ‘Ali, may Allah be pleased with him, narrated to us, he said: "I saw the Messenger of Allah, peace and blessings of Allah be upon him, stand for a funeral, so we stood. And I saw him sit, so we sat."