Musnad Ahmad 31:142

Abu al-Nadr narrated to us, Abu Mu'awiyah Shayban narrated to us, from Matar ibn Tahman, from Abu al-Siddiq al-Naji, from Abu Sa'id al-Khudri, who said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "The Hour will not be established until a man from my household rules, with a high forehead and a hooked nose. He will fill the earth with justice, just as it was filled before him with oppression. He will remain for seven years."