Waiver of statutory rights against enforcing creditors requires an expression of will by the entitled debtor himself; a declaration by a third person present at the seizure binds the debtor only if that person is shown to be specially authorized to transmit or substitute the debtor’s will. Mere absence of the debtor from the seizure does not suffice to infer such authority. Where no special mandate or other circumstances establishing representation are proved, the third person’s waiver is ineffective and the debtor may later invoke the exempt character of the seized items.