What is the legal ruling regarding my grandfather's mortgaging of two plots of land for a sum of money 71 years ago, given that the borrower and his heirs were unaware of my grandfather's heirs until a lawsuit was filed to repay the mortgage?

If the loan amount has been repaid to your grandfather or his heirs, then the mortgage must be released and the land freed for the debtor's heirs. However, if the payment has not been made, then the creditors are not obliged to release the mortgage until the debt is settled. If the debtors are unable to pay, the mortgagee may refer the matter to the ruler to sell the mortgaged property and settle the debt from its proceeds. The mortgage must be officially registered to prove the mortgagee's right. The debtor's heirs must repay the original loan amount regardless of the currency's value at the time of repayment, because debts must be repaid in kind. The repayment of a deceased person's debt must occur before the distribution of the inheritance, because "the soul of a believer is suspended by his debt until it is paid off."