Sahih al-Bukhari, Hadith 6913

Narrated Abu Huraira: The Prophet 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 ‏" ‏‏.‏

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