The Messenger of Allah ﷺ said, "The saaibah" — and Khalaf bin Walid said, "the saaimah — is without liability, the well is without liability, the mine is without liability, and on buried treasure there is the fifth."Shaybi said, "Rikaz refers to ancient buried treasure."
قال رسول الله ﷺ: السائبة- وقال خلف بن الوليد: السائمة- جبار، والجب جبار، والمعدن جبار، وفي الركاز الخمس. قال الشعبي: الركاز: الكنز العادي.
Imam Ahmad narrated it (14810, 14592) through two routes from Abbad bin Abbad, from Mujalid, from Shaybi, from Jabir, who mentioned it. Mujalid is Ibn Saeed bin Umayr Hamdani, and there is disagreement about him. Bukhari had a favorable opinion of him, saying, "He is truthful." Hammad bin Zayd narrated from him, as found in Bazzar's Kashf Astar (894), and his narration from him is sound. Haythami mentioned it in Majma al-Zawaid and said (3/78), "Ahmad, Bazzar, and Tabarani in Awsat narrated it, and its narrators are reliable."On this subject there is also what was narrated from Abdullah bin Umar bin Khattab, who said, "A piece of gold was brought to the Messenger of Allah ﷺ, being the first charity that had come to him from a mine. He said, 'What is this?' They said, 'Charity from a mine of ours.' He said, 'There will be mines, and the worst of creation will be found in them.'"Tabarani narrated it in Awsat (3556) and Saghir (1/153) from Hatim bin Humayd Abu Adi Baghdadi, who said, Yusuf bin Musa Qattan narrated to us, who said, Asim bin Yusuf Yarbui narrated to us, who said, Sueir Khims narrated to us, from Zayd bin Aslam, from Ibn Umar, who mentioned it. Tabarani said, "No one narrated this hadith from Shuayr except Asim bin Yusuf." Khatib also recorded it in his Tarikh (8/248-249) in the biography of Hatim bin Humayd, without mentioning any criticism or endorsement of him. So he is counted among the unknown narrators. As for Haythami, he said in Majma al-Zawaid (3/78), "Its narrators are the narrators of the Sahih," but this is not correct.As for what was narrated from Anas bin Malik, who said, "We went out with the Messenger of Allah ﷺ to Khaybar, and a companion of ours went into a ruin to relieve himself. He picked up a clod of earth to clean himself with, and it crumbled over him revealing gold. He took it and brought it to the Prophet ﷺ and told him about it. He said, 'Weigh it.' So he weighed it, and it was two hundred dirhams. The Prophet ﷺ said, 'This is a buried treasure, and it carries a fifth.'" This is daif.Imam Ahmad narrated it (12298), as did Bazzar in Kashf Astar (893) and Bayhaqi (4/155), all through the route of Abu Amir, who said, Zuhayr narrated to us, who said, Abdul-Rahman bin Zayd narrated to me, from his father, that Anas told him, and he mentioned it. Bazzar said, "We do not know it from Anas except through this route, and Zayd did not narrate from Anas except this." I say, its chain is daif because of Abdul-Rahman bin Zayd bin Aslam, whom the majority of scholars have graded daif. Ibn Hibban said, "He would reverse reports without realizing it." Bayhaqi also attributed the defect to him.Likewise, what was narrated from Ubada bin Samit is not sound, that he said, "Among the rulings of the Messenger of Allah ﷺ is that a mine entails no liability, a well entails no liability, and an animal is not liable for the injury it causes." By "animal" is meant livestock and other such creatures, and "no liability" means that no compensation is required. "And he ruled that buried treasure carries a fifth."Abdullah narrated it in his father's Musnad (22778) from Abu Kamil Jahdari, who said, Fudayl bin Sulayman narrated to us, who said, Musa bin Uqba narrated to us, from Ishaq bin Yahya bin Walid bin Ubada bin Samit, from Ubada, regarding the rulings of the Prophet ﷺ, and this was among them. Ibn Majah (2213) also recorded it through this route, as did Hakim (4/340), who said, "This is a hadith sahih according to the criteria of the two Shaykhs, though they did not record it." This is a mistake on his part, for the two Shaykhs did not record anything from Ishaq bin Yahya, rather it was Ibn Majah who recorded from him, and moreover he is "of unknown status," and he did not hear from Ubada bin Samit. Hence Daraqutni and others said, "This is a mursal hadith, Ishaq bin Yahya did not hear from Ubada bin Samit."On this subject there is also a report from Dubaa bint Zubayr bin Abdul-Muttalib bin Hashim, who narrated, saying, "Miqdad went out for his need at Baqi Khabkhaba, when a rat came out of a hole carrying a dinar. It kept bringing out one dinar after another until it had brought out seventeen dinars, then it brought out a red cloth, containing a dinar, making eighteen dinars in total. He took them to the Prophet ﷺ and told him about it, saying to him, 'Take its charity.' The Prophet ﷺ said to him, 'Did you reach down into the hole?' He said, 'No.' The Messenger of Allah ﷺ said to him, 'May Allah bless it for you.'"Abu Dawud (3087) and Ibn Majah (2508) narrated it through two routes from Musa bin Yaqub Zami, who said, my aunt Quraiba bint Abdullah narrated to me, that her mother Karima bint Miqdad bin Amr told her, from Dubaa bint Zubayr, and she mentioned it. In its chain is Quraiba bint Abdullah, from whom only her nephew Musa bin Yaqub narrated. Dhahabi mentioned her among the unknown women, and Ibn Hajar said in Taqrib, "Acceptable," meaning when corroborated, but I have not found any corroborator for her. As for Musa bin Yaqub Zami, his hadith is hasan when he does not contradict others and does not bring anything objectionable. His statement, "Did you reach into the hole," means did you take it out of the hole, in which case it would carry a fifth, because it would have the meaning of a buried treasure.There are other hadiths on this subject that are also not sound. See Majma al-Zawaid.