It is narrated from Hazrat Muhammad bin Ubaidullah that when the Holy Prophet (peace be upon him) sent Hazrat Mu'adh (may Allah be pleased with him) to Yemen as a judge, he said, "O Mu'adh! How will you judge?" Hazrat Mu'adh replied, "I will judge according to the Book of Allah." The Prophet (peace be upon him) said, "If a matter arises that is not in the Qur'an?" Hazrat Mu'adh replied, "I will judge according to the decision of the Messenger (peace be upon him)." The Holy Prophet (peace be upon him) said, "If a matter arises that is neither in the Qur'an nor has the Prophet (peace be upon him) decided about it, nor is there a decision from the righteous predecessors regarding it?" Hazrat Mu'adh (may Allah be pleased with him) replied, "I will do my best and make a correct decision based on my own effort and opinion." The Noble Prophet (peace be upon him) said, "All praise is due to Allah who has granted the messenger of the Messenger of Allah (peace be upon him) the ability to decide according to what pleases the Messenger of Allah (peace be upon him)."