It is permissible to take lost property in the Haram if it is small
Question

                I found some lost property in the Haram in Makkah, approximately ten to fifteen riyals. What is the ruling on that?.
Praise be to Allah.
    Insignificant lost property has no value; if one announces it, there is nothing wrong with that, and if one consumes it, there is nothing wrong with that, and if one gives it in charity, there is nothing wrong with that, because it is insignificant and may not be worth announcing it. Ten, twenty or thirty riyals and so on, nowadays such lost property is not important, so if you give it in charity on behalf of its owner, there is nothing wrong with it, and if you use it there is nothing wrong with it, and if you leave it there is nothing wrong with it. End quote.