The eleventh year of the hijrah, being the last year of Muhammed's life, was spent at Medina. There he settled the organization of the provincial and tribal communities which had adopted Islam and become the component parts of the Muslim federation. More officers had to be deputed to the interior provinces for the purpose of teaching their inhabitants the precepts of the religion, administering justice, and collecting zakat. Muadh Ibn Jabal was sent to Yemen. On his departure to that distant province the Prophet enjoined him to use his own discretion in the event of his being unable to find express authority in the Qur'an. Ali was deputed to Yamama in the southeast of the peninsula. To him the Prophet said: "Never decide between any two parties who come to you for justice unless you first hear both of them."