The Messenger of Allah ﷺ was asked about lost property, and he said, "Announce it for a year. If someone identifies it, hand it over. Otherwise, take note of its container, its tying string, and its count, then you may use it. If someone later identifies it, hand it over."
حدثنا أبو بكر الحنفي قال حدثنا الضحاك بن عثمان عن أبي النضر عن بسر بن سعيد
سئل رسول الله ﷺ عن اللقطة فقال عرفها سنة فإن اعترفت فأدها وإلا فاعرف عفاصها ووكاءها وعددها وإلا فكلها فإن اعترفت فأدها
Its isnad is sahih. Abu Bakr Hanafi is the younger one, whose name is Abdul-Kabir bin Abdul-Majid, and he is a trustworthy narrator of great renown. Dahhak bin Uthman is the Hizami, whom they deemed trustworthy, and his hadith is found in Sahih Muslim.This hadith was narrated by Bukhari 5/83, no. 2428, Fath al-Bari, in the chapter on lost property, stray sheep, and by Muslim 3/1349, no. 1722, similarly, and Abu Dawud 2/135, no. 1705, and Tirmidhi 3/646, no. 1372, who said it is hasan sahih, and Ibn Majah 2/838, no. 2506, and Bayhaqi 6/185.