Musannaf Ibn Abi Shayba 37:568

Abu Mu’awiyah narrated to us, from al-A’mash, from Thabit ibn ‘Ubayd, from Abu Ja’far al-Ansari, who said: I entered with the Egyptians upon Uthman. When they struck him, I went out running, and my cloak was filled with sweat, until I entered the mosque. There was a man sitting among about ten people, wearing a black turban. He said, "Woe to you, what is behind you?" I said, "By Allah, they have finished with the man." He said, "Woe to you at the end of time." I looked, and behold, it was Ali.