Sefer HaChinuch ספר החינוך

To not honor a great person in judgment: That the judge not honor one of the litigants at the time of the dispute — and even if he was great, honored and esteemed — as it is stated (Leviticus 19:15), “and do not dignify the face of a great man.” And they said in Sifra Kedoshim, Chapter 4:3, “That you not say, ‘This one is a wealthy man, he is the son of great ones. How can I shame him?’” — meaning to say that I should not honor him more than his opponent who is not great like him. “Hence it is stated, ‘and do not dignify the face of a great man.’”

And the root of the commandment is well-known, and I have written it at the beginning of the Order (Sefer HaChinukh 235).

And from the laws of the commandment is that which they, may their memory be blessed, said (Shevuot 30a) that it not be that one stand and one sit, but rather both of them stand. As in that they are in front of the court, it is fitting for them to stand as if they were in front of the Divine Presence; since the spirit of God dwells among the congregation of the judges of Israel, as it is stated (Psalms 82:1), “God stands in the congregation of God.” And nonetheless, they, may their memory be blessed, said (Shevuot 30b) that if they wanted to seat the litigants, the option is in their hand. And about what are these words speaking? At the time of give and take. But at the time of the final judgment, there is an obligation to stand, as it is stated (Exodus 18:13), “and the people stood over Moshe.” Except that all of the courts of Israel after the Talmud have become accustomed to seat them [in order to avoid] controversy. And even [regarding] the witnesses about whom it is written (Deuteronomy 19:17), “and the two men stand,” they have also become accustomed today to seat them (Mishneh Torah, The Sanhedrin and the Penalties within Their Jurisdiction 21:5). [This] and the rest of its details are elucidated in [various] places in Sanhedrin and Shevuot. (See Tur, Choshen Mishpat 17.)

And it is practiced in every place and at all times by males, since judgment is for them. And one who transgresses it and honors one litigant more than his fellow volitionally has violated this negative commandment and violated a positive commandment, as it is written (Leviticus 19:15), “you shall judge your people with righteousness.” And [regarding] that which, they may their memory be blessed, permitted an advantage for the sage over the ignoramus in a few of the commandments, we will write later on the next commandment adjacently (Sefer HaChinukh 235).