Musnad Ahmad 1018:134

Mu'awiyah ibn Hisham narrated to us, Sufyan narrated to us, from Humran ibn A'yan, from Abu al-Tufayl, from a certain son of Jariyah al-Ansari, who said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "Indeed, your brother, the Negus, has died, so pray over him."