Sunan Abi Dawud, Hadith 3061

Narrated Rabi'ah ibn AbuAbdurRahman: Rabi'ah reported on the authority of more than one person saying: The Messenger of Allah 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.

حَدَّثَنَا عَبْدُ اللَّهِ بْنُ مَسْلَمَةَ، عَنْ مَالِكٍ، عَنْ رَبِيعَةَ بْنِ أَبِي عَبْدِ الرَّحْمَنِ، عَنْ غَيْرِ، وَاحِدٍ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم أَقْطَعَ بِلاَلَ بْنَ الْحَارِثِ الْمُزَنِيَّ مَعَادِنَ الْقَبَلِيَّةِ وَهِيَ مِنْ نَاحِيَةِ الْفُرْعِ فَتِلْكَ الْمَعَادِنُ لاَ يُؤْخَذُ مِنْهَا إِلاَّ الزَّكَاةُ إِلَى الْيَوْمِ ‏.‏

sunnah.com