كتاب اللقطة
Read the English translation first, with the original Arabic directly underneath.
This hadith has been narrated on the authority of Rabi'a b. Abu Abd al-Rahman with the same chain of transmitters but with this addition:
" There came a person to Allah's Messenger (ﷺ) while I was with him, and he asked him about picking up of a stray article, and he said: When none comes to demand it, then spend that."
فَإِذَا لَمْ يَأْتِ لَهَا طَالِبٌ فَاسْتَنْفِقْهَا