Hazil narrates from Sayyiduna Abdullah (may Allah be pleased with him): I think he narrated it as a marfu‘ (attributed to the Prophet) hadith: "The death of a person caused by an animal (killing him) is in vain, the death by falling into a well is in vain, the death by falling into a mine is in vain, and in rikaz (buried treasure) payment of one-fifth is obligatory."