Once upon a time when Al-Hajjaj Ibn Yusuf Ats-Tsaqafi (who was famous for his cruelty) was bathing and swimming in the Persian Gulf, suddenly he was almost carried away by the water.  Then one of the Moslems saved him.  When the Moslem brought him ashore. Al-Hajjaj said to him, "Ask what you want, because I will grant your request."  So the Muslim asked, "Who are you that you can grant all requests?"  He replied, "I am Al-Hajjaj ats-Tsaqafi."  The Moslem said, "My only wish is that I ask you not to tell anyone that I have saved you."

Translated from "101 Kisah Teladan"  written by  Muhammad Amin al-Jundi, Indonesian translation by Safrudin Edi Wibowo, Lc