Must a sum of money obtained by deceit be given in charity, when its owner has forgiven the debt of the loan and was not informed of the deceit?

If a person waives their right because the petitioner deceived them into believing they needed money for family matters, then this waiver is not valid. And if they gave him money based on the assumption of this need, the petitioner does not own the gift if the reality was not as the giver presumed. So, whoever is given something because of a characteristic the giver assumes they possess, such as poverty, when in reality they are not, it is unlawful for them to take it. And if the petitioner is obliged to return this money to its owner and it is not possible, then they should donate it on the owner's behalf.