What is the ruling of Islamic law regarding a dispute over the debt of a deceased father: Is the mother obliged to share with the creditor the lost business asset, should the debt be repaid at its value at the time of borrowing or at its current value with the change in exchange rates, and is it permissible to give the money in charity if the creditor refuses to receive it?

The dispute between the questioner's mother and his father's friend regarding the nature of the amount paid to his father can only be resolved by distinguishing the truthful from the liar. This falls under the jurisdiction of the Sharia court, which relies on evidence from the claimant and an oath from the one who denies. Therefore, everyone is advised to reconcile.

As for the fluctuation in currency value, it does not affect a debt. Whoever borrows a currency repays it as he received it, and is not obligated to pay more or less.

If the creditor refuses to accept the two thousand owed to him, do not give it away as charity. Instead, keep it with you, documenting this fact, and if the man dies, it should be paid to his heirs.