'Abd al-Rahman b. 'Uthman al-Taimi reported that Messenger of Allah ﷺ forbade taking into custody the stray thing of the pilgrims.  

أَنَّ رَسُولَ اللَّهِ ﷺ نَهَى عَنْ لُقَطَةِ الْحَاجِّ  

He who found a stray article is himself led astray if he does not advertise it.  

عَنْ رَسُولِ اللَّهِ ﷺ أَنَّهُ قَالَ مَنْ آوَى ضَالَّةً فَهُوَ ضَالٌّ مَا لَمْ يُعَرِّفْهَا