Deuteronomy 16:18-20 Judges and officers shalt thou make thee in all thy gates, which the LORD thy God giveth thee, throughout thy tribes: and they shall judge the people with just judgment. (19) Thou shalt not wrest judgment; thou shalt not respect persons, neither take a gift: for a gift doth blind the eyes of the wise, and pervert the words of the righteous. (20) That which is altogether just shalt thou follow, that thou mayest live, and inherit the land which the LORD thy God giveth thee.
God commanded his people to institute a civil government of men. Its activities must be carried out in the open (in the city gates). It may never favor a poor man over a rich man, a white man over a black man, a Jew over a gentile, a man over a woman, or vice versa. It may never accept payment from any party to a lawsuit or a criminal trial. It must always do what is righteous. “Just” in verse 20 was translated from the Hebrew tzedek, which means “righteousness”. It’s the same word David used in Psalms 119:144 referring back to this passage:
The righteousness of thy testimonies is everlasting: give me understanding, and I shall live.
The same Psalm further defines tzedek in verse 172:
My tongue shall speak of thy word: for all thy commandments are righteousness.
That government is best which governs according to all God’s commandments, neither adding to them nor taking away from them.