If someone finds money, gold, or precious items in his commodity without the seller's knowledge of their existence,
are these items considered part of the buyer's possession or not?
If the owner of the merchandise does not know about this precious item, then it will not be included within the transaction, because this transaction does not specifically include it. Therefore, the buyer should return it to the seller, after making sure that he is the owner of that precious item. If it does not belong to the seller, then the buyer should return it to its real owner after announcing it. If he cannot know the real owner of that precious item, then he should give it away as charity with the intention that (Part No. 13; Page No. 88) the reward of the charity goes to its real owner. If, later on, its owner appears and asks for it, then the buyer should pay him its value, and the reward of the charity will be, In sha’a-Allah (if Allah wills), for the giver (i.e. the buyer).
May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.