The money which is received by the mortgagee, arising from the sale, after discharge of prior incumbrances to which the sale is not made subject, if any, or after payment into court under this Act of a sum to meet any prior incumbrance, shall be held by him in trust to be applied by him, first, in payment of all costs, charges, and expenses properly incurred by him as incident to the sale or any attempted sale, or otherwise; and secondly, in discharge of the mortgage money, interest, and costs, and other money, if any, due under the mortgage; and the residue of the money so received shall be paid to the person entitled to the mortgaged property, or authorised to give receipts for the proceeds of the sale thereof.