A man asked, "Messenger of Allah, what about stray camels, may we take them?"He replied, "A Muslim's lost property is the fire of Hell."
حدثنا يحيى بن سعيد قال حدثنا حميد يعني الطويل حدثنا الحسن
أن رجلا قال يا رسول الله هوام الإبل نصيبها قال ضالة المسلم حرق النار
Its isnad is sahih. The hadith is found in Tirmidhi 4/301, no. 1881, in the chapter on beverages, what has been narrated regarding the prohibition of drinking while standing, and Ibn Majah 2/836, no. 2502, and Darimi 2/344, no. 2601.