Is it obligatory to inform the grandfather about finding a gold ring and expensive watches among old goods, knowing that he was in a hurry and did not pay much attention to many of the box's contents?

If the grandfather gifted what was in the box without knowing its contents, the validity of the gift is disputed. The majority opinion is that it is not valid, especially if the ignorance was on the part of the giver. It is possible that ignorance on the part of the giver prevents validity, whereas it does not prevent it if it is on the part of the recipient. The grandfather must be informed of what was found in the box. If he gives it willingly, there is no harm in taking it; otherwise, it is his property, and it is not permissible to take it without his consent.