514 – From Abu Hurayrah (may Allah be pleased with him): the Messenger of Allah ﷺ said, “One-fifth is due on rikāz (pre-Islamic buried treasure).” Agreed upon. ⦗1⦘

515 – From ʿAmr ibn Shuʿayb, from his father, from his grandfather (may Allah be pleased with them): the Messenger of Allah ﷺ said, “As for a hoard a man finds in a ruin: if you discover it in an inhabited village, announce it publicly; but if you find it in an uninhabited village, then on it—and on rikāz—one-fifth is due.” Reported by Ibn Mājah with a hasan chain. ⦗2⦘

Hadith grading
This ḥadīth is hasan, for it is supported by authentic corroborations, among them the wording recorded by the two Ṣaḥīḥs and others from Abu Hurayrah: “One-fifth is due on rikāz.” Al-Ḥāfiẓ said, “Its transmitters are trustworthy, and it possesses a strong mursal corroboration that comes through the route of ʿAlī ibn Abī Ṭālib (may Allah be pleased with him).”

Vocabulary
• khirbah: a deserted house or ruin (plural: khirab).
• faʿarrifhu: the imperative of taʿrīf, meaning: make it known among the people—announce it—until its owner comes forward or a full year passes.