Midrash sa Deuteronomio 16:21: Devarim Rabbah, Midrash Tanchuma Buber, Mekhilta DeRabbi Yishmael & Midrash Tanchuma

Another interpretation, “judges and officers” – Rav Aḥa said: Come and see that Solomon’s throne had six stairs. From where is this derived? It is as it is stated: “There were six stairs to the throne” (I Kings 10:19). And in this passage, six matters are written as negative commandments, and they are: “You shall not distort judgment, you shall not give preference, and you shall not take a bribe” (Deuteronomy 16:19); “You shall not plant for you any kind of sacred tree” (Deuteronomy 16:21); “You shall not establish a monument for you” (Deuteronomy 16:22); “You shall not slaughter to the Lord your God an ox, or a lamb, [in which there is a blemish]” (Deuteronomy 17:1). There you have six. The herald would stand before Solomon’s throne, and when he [Solomon] would ascend the first stair, he would proclaim: “You shall not distort judgment”; for the second stair he would proclaim: “You shall not show preference”; for the third, he would proclaim: “And you shall not take a bribe”; for the fourth: “You shall not plant for you any kind of sacred tree”; for the fifth: “You shall not establish a monument for you”; for the sixth: “You shall not slaughter to the Lord your God […in which there is a blemish].”
Rabbi Ḥiyya bar Abba said: The protocol for a trial is as follows: The plaintiff states his claim, the defendant responds, and the judge renders a decision. Rabbi Sima said: The judge must orally review their claims. From whom can you learn this? From Solomon, as it is stated: “The king said: This one says: This is my living son, and your son is the dead one; and that one says: No, rather, your son is the dead one, and my son is the live one” (I Kings 3:23).
Rabbi Yehuda ben Rabbi Ilai said: I heard that if a judge wishes to seat the litigants, he may seat them. What is it that is prohibited? There may not be one [litigant] sitting and the other one standing, as Rabbi Yishmael said: If there was a judge and two people came to him for judgment, one wealthy and one impoverished, he should say [to the wealthy one]: ‘Dress as he is dressed, or dress him as you are dressed.’
“You shall not show preference” (Deuteronomy 1:17) – Rabbi Elazar and Rabbi Shmuel bar Naḥman, Rabbi Elazar said: If you [the judge], realize that justice is in his favor [one of the litigants], do not show him a favorable countenance, so he [the other litigant] should not say: ‘From the outset he sought to rule in his favor.’ Rabbi Shmuel bar Naḥman said: If you [the judge] know that justice is not in his favor, show him a favorable countenance, so he should not say: ‘From the outset he sought to convict me.’ Rabbi Ḥanina said: One verse says: “You shall judge fairly” (Deuteronomy 1:16),¹³This verse does not mention extensive investigation of the claims. and another verse says: “You shall inquire, interrogate, and ask diligently” (Deuteronomy 13:15). How can this be [resolved]? If you sense that the case [presented by one of the litigants] is fraudulent, interrogate him, but if you sense that the case is being resolved truthfully, judge him fairly.¹⁴Without interrogation.

Another interpretation (of Deut. 16:19): YOU SHALL NOT TURN ASIDE JUSTICE. <Here is> a warning for a wise person not to seat someone beside one who is unfit for jurisdiction. Moreover, if he should so seat someone, it is as though he had planted an Asherah. So near <this verse> is <the following> (in Deut. 16:21): YOU SHALL NOT PLANT FOR YOURSELVES ANY TREE AS AN ASHERAH <BESIDE AN ALTAR OF THE LORD YOUR GOD…. > There is a story about a certain person who had a lawsuit with a king, one of the kings of the Hasmonean dynasty.²⁷Sanh. 19a; cf. Josephus, Ant. 14:168–184, for a similar story about Herod being charged with murder. He came and stood before Simeon ben Shetah. He said to him: I have a lawsuit with the king. Simeon ben Shetah said to those judges who were judging along with him: If I send for the king, will you reprimand him? They told him: Yes. He sent for him. He came and put his throne beside Simeon ben Shetah. Simeon ben Shetah said to him: Stand on your feet and give satisfaction. He said to him: Are they judging the king? He turned to the right, and the judges <on the right> pressed their faces on the ground (to hide them). He turned to the left, and < those on the left> pressed their faces on the ground. The angel²⁸The parallel in Tanh., 5:7 identifies the angel with Gabriel. came and beat them on the ground, until their breath left them. Immediately the king trembled. Simeon ben Shetah said to him: Stand on your feet and give satisfaction, since you are not standing before us but before the one who spoke and the world came into being. He immediately stood on his feet and gave satisfaction. From here it follows that litigants conduct themselves in awe. They are rendering judgment, as it were, before the Holy One. Therefore Jehoshaphat said to the judges (in II Chron. 19:6): CONSIDER [WHAT YOU ARE DOING], SINCE YOU ARE NOT RENDERING JUDGMENT FOR HUMANS BUT FOR THE LORD. R. Hama bar Hanina said: Come and see! If there it no scriptural text written, it is not possible for him to say that flesh and blood judges its creator. The Holy One said to the Judges: Let them conduct themselves in awe, as if you were judging me. How? One fulfills a commandment before me. I have decreed over him to give him a hundred fields. If you pass judgment against him on one thing that I have decreed over him, I will give him other <fields> from what I possess; and I will credit it against you as though you had gotten it from me.

(Ibid. 4) "You shall not make for yourself an idol (lit., "a carving")": I might think that he may not make one that projects but he may make one that is flat. It is, therefore, written "any likeness." I might think that he may not make a flat one, but that he may make (an idol of) a planting. It is, therefore, written (Devarim 16:25) "You shall not plant for yourself an asheirah." I might think that he may not plant one, but that he may make one of wood. It is, therefore, written (Ibid.) "any wood." I might think that he may not make one of wood, but that he may make one of stone. It is, therefore, written (Leviticus 26:1) "And a covering stone, etc." I might think that he may not make one of stone, but that he may make one of silver. It is, therefore, written (Exodus 20:20) "gods of silver." I might think that he may not make one of silver, but that he may make one of gold. It is, therefore, written (Ibid.) "and gods of gold." I might think that he may not make one of gold, but that he may make one of copper or tin or lead. It is, therefore, written (Exodus 34:13) "Molten gods you shall not make for yourself." I might think that he may not make for himself the likeness of all these but that he may make one of any form. It is, therefore, written (Devarim 4:16) "Lest you corrupt yourselves and make … of any form." I might think that he may not make one of any form, (of human being), but that he may make one of the likeness of an animal, beast, or bird. It is, therefore, written (Ibid. 17) "the figure of any beast, etc." I might think that he may not make the likeness of all of these, but that he may make the likeness of fish, hoppers, reptiles, and creeping things. It is, therefore, written (Ibid. 19) "any thing that creeps on the ground." I might think that he may not make the likeness of sun, moon, stars, and constellations. It is, therefore written (Ibid. 19) "And lest you lift your eyes to the heavens, etc." I might think that he may not make the likeness of any of these, but he may make the likeness of angels, cherubs, ofanim and chashmalim (angelic entities). It is, therefore, written (Ibid. 39) "in the heavens." If "in the heavens," I might think that he may not make the likeness (only) of sun, moon, and stars. It is, therefore, written (Ibid.) "above" — neither the likeness of cherubs or ofanim. I might think that he may not make the likeness of all these, but he may make the likeness of the depths or of darkness. It is, therefore, written