The Book of Found Property (luqṭa)
In the name of Allah, the Most Compassionate, the Most Merciful. May Allah bless our master Muhammad, his family, and his Companions, and may He likewise bless him after whom there is no prophet.
According to Mālik, picking up a lost item is not obligatory unless one fears that, if left, it will disappear or be ruined. In such a case—or whenever the object is of real value—one should take it and not leave it. If, however, the item is insignificant, it should be left where it is.
Whoever retrieves a lost article that had been kept in a secure place and then returns it to that place after taking it becomes liable for any loss or damage that follows. Conversely, if he picks it up supposing it belongs to some people he sees ahead of him, then catches up with them and no one claims it, he may choose either to retain it while making it publicly known, or to put it back where he found it; in either case he incurs no liability.
It is also transmitted from Mālik that if the finder knows the owner of the lost property, it is commendable—but not mandatory—for him to pick it up. If he does not know the owner, he is free to leave it. Nonetheless, when the article consists of gold dinars, silver dirhams, or any other item of significance, Mālik prefers that it be taken rather than left.
Whoever finds something other than a living animal—whether gold, silver, clothing, or another type of merchandise