Negative Commandment #65
65. It is a negative commandment "a judge should not listen to one person's side with the other person not being present."
As it states in Shemos (Exodus) 23:1, "you shall not accept a false report." This also warns the litigant not to tell his statements to the judge before the other litigant is present. Therefore, we read the words 'lo sisa' as 'lo sasi', which means you shall not cause him to accept.
Included in this negative commandment is not to accept or speak lashon hara, nor to give false testimony.
This applies in all places and at all times, for judges and litigants, that are men and women.