Hadith 5:980
Al-Fadl ibn Dukayn narrated to us, from Isra'il, from Simak, from 'Ikrimah, from Ibn 'Abbas, from the Prophet (may Allah bless him and grant him peace), who said: The Prophet (may Allah bless him and grant him peace) decreed regarding buried treasure (rikaz) one-fifth.
حدثنا الفضل بن دكين عن إسرائيل عن سماك عن عكرمة عن بن عباس عن النبي صلى الله عليه وسلم قال قضى النبي صلى الله عليه وسلم في الركاز الخمس