When a legal or judicial mortgage securing an indebtedness due by a former owner of property is sought to be enforced against the property after its acquisition by a third possessor, the latter may plead discussion to compel the mortgagee to enforce the mortgage against other property affected thereby, which is owned by the mortgagor, or which has been acquired from the mortgagor by a third person after the third possessor acquired his property.
La. C.P. § 5154