Amr bin Shu'ayb narrates from his father, and he from his grandfather (may Allah be pleased with him), that he said: I heard a man from Muzaynah (may Allah be pleased with him) ask the Messenger of Allah (peace and blessings be upon him) about a stray camel while I was listening. He (peace and blessings be upon him) said: "It has its hooves and its water supply with it; the wolf cannot eat it; it drinks water and can eat the leaves of trees. Leave it in its place until the one looking for it comes." He asked about a stray sheep, and he (peace and blessings be upon him) said: "It is for you, or for your brother, or for the wolf; keep hold of it until the one looking for it comes." He said: "And a found item that we come across?" He (peace and blessings be upon him) said: "Whatever is in an inhabited place or on a frequented road, announce it for a year; if the one looking for it comes, give it to him, otherwise it is yours." He asked: "O Messenger of Allah, what is found in an ancient ruined place?" He (peace and blessings be upon him) said: "In it and in buried treasure (rikaz) there is one fifth (khumus)." In one narration he said: "What is your view about a stray sheep?" He (peace and blessings be upon him) said: "It is food to be eaten, for you, or for your brother, or for the wolf. Keep your brother's stray for him."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب اللقطة / 12068