When the Prophet صلى الله عليه وسلم sent Mu’adh as a governor to Yemen, he صلى الله عليه وسلم said to him, “What are you going to rule by?” Mu’adh said, “By the Qur’an of Allah.” The Prophet صلى الله عليه وسلم then asked, “If you don’t find (the rule)?” He said, “By the Sunnah of the Messenger صلى الله عليه وسلم of Allah.” The Prophet صلى الله عليه وسلم said, “If you don’t find (the rule)?” Mu’adh said, “I exert my utmost and give my opinion.” The Prophet صلى الله عليه وسلم said, “Alhamdu Lillah (Praise be to Allah) that He led the Messenger of Allah to that which Allah and His Messenger like.”