law: Transfer of Property Act, 1882
  56. Marshalling by subsequent purchaser
  If the owner of two or more properties mortgages them to one
  
  person and then sells one or more of the properties to another person, the
  
  buyer is, in the absence of a contract to the contrary, entitled to have the
  
  mortgage-debt satisfied out of the property or properties not sold to him, so
  
  far as the same will extend, but not so as to prejudice the rights of the
  
  mortgagee or persons claiming under him or of any other person who has for
  
  consideration acquired an interest in any of the properties.