Section 57. It shall be unlawful for a mortgagee to enforce, in any mortgage note secured by a first lien on a dwelling house of three or less separate households occupied or to be occupied in whole or in part by the mortgagor, a penalty, charge, premium, or fee on account of payment of the amount due before the date fixed for payment, when such payment is made on the occasion of a taking of the property for any public purpose.