Responsa for Shevuot 61:16
בפני בית דין ושלא בפני ב"ד כו': במאי קמיפלגי
R'Kahana learnt [these deductions] from: Thou shalt not utter [a false report]:<span class="x" onmousemove="('comment',' Ex. XXIII, 1, lit., 'thou shalt not take up, or accept'; a warning to the judge not to hear one litigant before the arrival of the other, because the litigant, in his opponent's absence, may be tempted to lie. ta,');"><sup>14</sup></span> thou shalt not cause to be uttered.<span class="x" onmousemove="('comment',' Reading the same Hebrew word, , with different vowels (the Hiphil) : 'thou shalt not cause to be accepted'; a warning to the litigant not to explain his case to the judge in his opponent's absence, because he may be tempted to lie, and will thereby cause the judge to accept a false report, v. Sanh. 7b.');"><sup>15</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.
Teshuvot Maharam
A. A cannot have his friends present at the trial, neither can the partners be present while one of them presents his claims, so that A may not be confronted with all the partners at the same time. Each partner shall present his claims separately and the verdict shall be passed on the accumulated evidence. If the court finds difficulty in remembering all the facts and claims, let the partners present their claims before two or three courts, or in two or three days to the same court, or let the court keep a written record of all claims.
SOURCES: Pr. 333; Mord. Shebu. 761; Rashba I. 1107.