Sahih al-Bukhari 6913
Narrated Abu Huraira:
The Prophet (ﷺ) said, "There is no Diya for a person injured or killed by an animal (going about without 
somebody to control it) and similarly, there is no Diya for the one who falls and dies in a well, and 
also the one who dies in a mine. As regards the Ar-Rikaz (buried wealth), one-fifth thereof is for the 
state."
حَدَّثَنَا مُسْلِمٌ، حَدَّثَنَا شُعْبَةُ، عَنْ مُحَمَّدِ بْنِ زِيَادٍ، عَنْ أَبِي هُرَيْرَةَ ـ رضى الله عنه ـ عَنِ النَّبِيِّ صلى الله عليه وسلم قَالَ ‏
"‏ الْعَجْمَاءُ عَقْلُهَا جُبَارٌ، وَالْبِئْرُ جُبَارٌ، وَالْمَعْدِنُ جُبَارٌ، وَفِي الرِّكَازِ الْخُمُسُ ‏"‏‏.‏