Is it permissible to donate a small amount of less than ten Jordanian Dinars, which the father borrowed before his death from an unknown person who cannot be reached, or to buy something for the mosque with its value?

If it is impossible to identify the owner of the money, it is permissible to donate the amount on their behalf or to spend it on the welfare of Muslims. This is the view of the majority of scholars, such as Malik and Ahmad, who cite the actions of the Companions and their successors, and the Almighty's saying: "Allah does not burden a soul beyond its capacity," and His saying: "So fear Allah as much as you are able."