Responsa for Shevuot 61:8
מנין לנושה בחבירו מנה וטענו מאתים שלא יאמר אכפרנו בב"ד ואודה לו חוץ לבית דין כדי שלא אתחייב לו שבועה ולא יגלגל עלי שבועה ממקום אחר תלמוד לומר מדבר שקר תרחק
How do we know that he who has a claim of a hundred zuzim against his neighbour should not say, 'I will claim two hundred, so that he will admit a hundred, and be liable for an oath,<span class="x" onmousemove="('comment',' He who admits a portion of a claim () takes an oath that he owes no more, and is exempt. kfv rpuf');"><sup>7</sup></span> then I will be able to impose an oath upon him from another place'?<span class="x" onmousemove="('comment',' I.e., in connection with another claim which he totally denied () , and for which no oath could be imposed; but since he has to take an oath in this case, the court can at the same time include the previous claim in the oath.');"><sup>8</sup></span>
Teshuvot Maharam
A. The statement in the Palestinian Talmud does not necessarily imply that an ordinary person is permitted to appoint a legal representative. It is possible that only a high priest is permitted to appoint such a representative, in order to save him the humiliation of appearing before a court having less authority than himself; but an ordinary person may not be permitted to make the appointment. In any case, all are agreed that a levir is not permitted to appoint a legal representative when his brother's widow demands that he fulfill the positive command (of God) to perform the ceremony of halitzah or to marry her. Moreover, a person commits a wrong when he consents to become a legal representative to a levir, thus helping to postpone the fulfillment of this positive command, and injuring the interests of the widow.
b) Q. Is a legal representative permitted to present before the court claims and arguments that will improve his client's case but which he knows to be false?
A. The plaintiff, or defendant, himself is not permitted to lie in order to improve his case in court; a legal representative, therefore, is surely not permitted to lie.
SOURCES: Cr. 246; L. 126, 127; Mord. B. M. 276; cf. P. 519; Mordecai Hagadol, p. 270a.
Teshuvot Maharam
A. The plaintiff, or defendant, himself is not permitted to lie in order to improve his case in court; a legal representative, therefore, is surely not permitted to lie.
SOURCES: Cr. 246; L. 126, 127; Mord. B. M. 276; cf. P. 519; Mordecai Hagadol, p. 270a.