It is narrated from Hazrat Abu Saeed Khudri (may Allah be pleased with him) that the Prophet (peace and blessings be upon him) said: The Day of Judgment will not be established until a man from my Ahl al-Bayt, with a broad forehead and a prominent nose, becomes the caliph. He will fill the earth with justice and fairness just as it was previously filled with oppression and injustice, and he will remain for seven years.
Hadith Referenceمسند احمد / مسند المكثرين من الصحابة / 11130
Hadith Gradingحکم دارالسلام:حديث صحيح دون قوله: يكون سبع سنين، مطر الوراق- وإن كان فيه ضعف من جهة حفظه - متابع