Must a father return the value of gold he sold with his daughter's consent, and what is the method of restitution?

If the gold was given to the father as a gift, then his liability is absolved. However, if it was a loan and there is proof of it, then it is considered a debt upon him and should be paid from his estate, if he leaves one, in accordance with the Almighty’s saying: {after any legacy he may have bequeathed or any debt}. If he did not leave any wealth, then the children are not obligated to pay the debt, though it is commendable for them to do so.