הלכה על אבות 1:8

Traditional sources also seem to discourage the presence of lawyers in beit din in order to preserve the “innocence” of the litigants. For example, the Rama (C.M. 17:5) rules that a Torah scholar should not inform a litigant whether his position is correct, lest the litigant deduce from the information how to fraudulently win his case. The Mishnah (Avot 1:8) prohibits acting as an attorney (k’orchei hadayanim). In his commentary to the Mishnah (ad loc.), the Rambam explains that one should not coach a litigant by teaching him which claims will help him win the case.³Not all commentators accept the Rambam’s interpretation of “orchei hadayanim.” See Rashi and Midrash Shmuel on this Mishnah for a variety of interpretations of “orchei hadayanim.” The Rambam adds that this prohibition applies even when one knows that the litigant deserves to win. Even in such a case, the litigant must present the facts truthfully to the beit din and may not lie in order to ensure his victory. Similarly, the Gemara (Ketubot 52b) discourages Torah scholars from advising individuals (offering “lawyerly” advice) even outside the context of beit din.