Rabi'ah reported on the authority of more than one person saying: The Messenger of Allah ﷺ assigned as a fief to Bilal ibn al-Harith al-Muzani the mines of al-Qabaliyyah which is in the neighbourhood of al-Fur', and only zakat is levied on those mines up to the present day.
أَنَّ رَسُولَ اللَّهِ ﷺ أَقْطَعَ بِلاَلَ بْنَ الْحَارِثِ الْمُزَنِيَّ مَعَادِنَ الْقَبَلِيَّةِ وَهِيَ مِنْ نَاحِيَةِ الْفُرْعِ فَتِلْكَ الْمَعَادِنُ لاَ يُؤْخَذُ مِنْهَا إِلاَّ الزَّكَاةُ إِلَى الْيَوْمِ