The Prophet ﷺ said: He who finds something should call one or two trusty persons as witnesses and not conceal it or cover it up; then if he finds its owner he should return it to him, otherwise it is Allah's property which He gives to whom He will.
قَالَ رَسُولُ اللَّهِ ﷺ مَنْ وَجَدَ لُقَطَةً فَلْيُشْهِدْ ذَا عَدْلٍ أَوْ ذَوَىْ عَدْلٍ وَلاَ يَكْتُمْ وَلاَ يُغَيِّبْ فَإِنْ وَجَدَ صَاحِبَهَا فَلْيَرُدَّهَا عَلَيْهِ وَإِلاَّ فَهُوَ مَالُ اللَّهِ ﷻ يُؤْتِيهِ مَنْ يَشَاءُ