The Messenger of Allah ﷺ said, "A lost item belonging to a Muslim is a flame of the Fire."
حدثنا محمد بن المثنى حدثنا يحيى بن سعيد عن حميد الطويل عن الحسن
قال رسول الله ﷺ ضالة المسلم حرق النار
[Sahih]. Ahmad narrated it, 25/4, from Yahya bin Saeed, who said, "Humayd, meaning Tawil, narrated to us, saying, ..." and Ibn Hibban graded it sahih in Mawarid, hadith 1171, as did Busiri, and Diya Maqdisi in al-Awsat and al-Mukhtarah.Hasan followed him, with Qatada narrating it as well, as found in Abu Naeem's al-Hilyah, 33/9, and before him, Tabarani, page 329, hadith 1570, where Shuba narrated it from him, and the chain up to him is sahih. The hadith has many corroborating narrations.