Sayyiduna Abu Sa'id Khudri (may Allah be pleased with him) narrates that the Prophet (peace and blessings of Allah be upon him) said: "The Hour will not be established until a man from my Ahl al-Bayt becomes a ruler; he will fill the earth with justice just as it was filled with oppression before him. He will rule for seven years."
(Imam Ibn Hibban, may Allah have mercy on him, says:) The narrator named Abu Sadiq is Bakr bin Qais Naji.