The surrender, made voluntarily by a creditor to his debtor, of a private instrument proving a credit, implies the renunciation of the action which the former had against the latter.\nIf in order to invalidate this renunciation, it should be claimed that it is illegal, the debtor and his heirs may support it by proving that the delivery of the instrument was made by virtue of the payment of the debt.\nHistory —Civil Code, 1930, § 1142.
Puerto Rico Legal Code