Musnad Ahmad 28:414

Ibn Idris narrated to us, I heard Ibn Ishaq, from ‘Amr ibn Shu‘ayb, from his father, from his grandfather, who said: I heard the Messenger of Allah (ﷺ) while a man from Muzaynah was asking him about a stray camel. He said: "It has its footwear and its water-skin with it; it eats the trees and drinks the water, so leave it until its owner comes looking for it." He said: And he asked him about a stray sheep. He said: "It is for you, or for your brother, or for the wolf; gather it to yourself until its owner comes looking for it." And he asked him about the *harisah* (stolen sheep) that is found in its grazing lands. He said: "In it is its price twice over, and a disciplinary punishment." He said: "And what is taken from its resting places, in it is the cutting [of the hand], when what is taken of that reaches the price of a shield." Then he asked him, saying: O Messenger of Allah, what about a lost item we find on a populated road? He said: "Make it known for a year; if its owner comes, [give it to him], otherwise it is yours." He said: O Messenger of Allah, what about what is found in ancient ruins? He said: "In it, and in buried treasure (*rikaz*), is one-fifth."