Mass. Gen. Laws ch. 223, § 107: Affidavit and bond

Section 107. The petitioner, or a person in his behalf, shall make oath that his claim is just and legal and that all the other facts stated in the petition are true or are believed by the deponent to be true; and, upon filing the petition, the petitioner, or a person in his behalf, shall give a bond or recognizance with sufficient surety, conditioned to pay to the adverse party such damages and costs as may be awarded to him upon the petition.