The judge should not fear a party in the lawsuit.
“Do not be afraid of the presence of any man” Devarim 1:17
Even if the man on trial is powerful he should not be afraid that he may harm him.
As long as the judge does not know the direction of justice in the case he can remove himself saying “I am not bound to try your case”
However, once he hears their statements and knows where justice lies he cannot remove himself because he fears one party may injure him.
Included in a violation of this prohibition is where a disciple sitting before his master who sees a point in favour of a poor man and disadvantage of the rich man, yet he remains silent.
This applies in every place at all times