Lands mortgaged to secure the payment of debts or the performance of any collateral engagement, and the debts so secured are, on the death of the mortgagee or person claiming under him, assets in the hands of his executors or administrators. They shall have the control of them as of a personal pledge. When they recover seizin and possession thereof, it shall be for the use of the widow and heirs, or devisees or creditors of the deceased, as the case may be. When redeemed, they may receive the money, and give effectual discharges therefor, and releases of the mortgaged premises.