Silsilah as-Sahihah 3637 — Story of Imam Mahdi

Muawiyah bin Qurrah narrates from his father that the Messenger of Allah (peace and blessings be upon him) said: "The earth will be filled with oppression and injustice; when this happens, Allah Almighty will send a man, he will have my name, and he will fill the earth with justice and fairness in place of oppression and injustice."