Negative commandment · Lo Ta’aseh #273 of 613
Not to act deceitfully in judgment
שלא לעוול המשפט
The verse · Vayikra 19:15
לֹא־תַעֲשׂוּ עָוֶל בַּמִּשְׁפָּט לֹא־תִשָּׂא פְנֵי־דָל וְלֹא תֶהְדַּר פְּנֵי גָדוֹל בְּצֶדֶק תִּשְׁפֹּט עֲמִיתֶךָ
“You shall do no unrighteousness in judgment: thou shalt not respect the person of the poor, nor honour the person of the mighty: but in righteousness shalt thou judge thy neighbour.”
The Rambam’s words
Not to act deceitfully in judgment, as [Leviticus 19:15] states: "Do not pervert justice."
שלא לעוול המשפט, שנאמר "לֹא תַעֲשׂוּ עָוֶל בַּמִּשְׁפָּט" (ויקרא יט, טו).
Why · Sefer HaChinuch #233
To not vitiate justice
“The root of this commandment is well-known, since the civilization of men is preserved with righteous judgment.”
Who & when
“And it is practiced in every place and at all times by males, since judgment is for them.”
Where in the Mishneh Torah
Hilchot The Sanhedrin and the Penalties within Their Jurisdiction הלכות סנהדרין והעונשין המסורין להם