The Prophet (peace and blessings be upon him) granted Bilal bin al-Harith al-Muzani (may Allah be pleased with him) the mines of al-Qabaliyyah, in the direction of al-Fur', as a fief. Nothing was taken from those mines except zakah, up to this day.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب إحياء الموات / 11841