Midrash su Deuteronomio 21:5

(Deuteronomy 16:18) "You shall appoint judges and officers in all your towns that the Lord your God is giving you, according to your tribes, and they shall judge the people with righteous judgment." - Halacha: Can one sit in judgement for one's relative? Such taught the sages: These are the relatives: his father, his brother, his paternal uncle, his maternal uncle, etc. Why is this so? Because just like a relative is invalid to testify [regarding him], so too he is invalid to judge. What did you see to say this? Rabbi Shimon bar Yochai said: It is written (Deuteronomy 21:5), "Then the priests, the sons of Levi, shall come forward, for the Lord your God has chosen them to minister to him and to bless in the name of the Lord, and by their word every dispute and every skin affliction shall be settled." - Come and see the relationship between skin afflictions and disputes. Just like skin afflictions [are examined] during the day, so too judgement [are done] during the day. Just like disputes are to the exclusion of relatives [as witnesses], so too skin afflictions are to the exclusion of relatives [as examiners]. Rabbi Shimon ben Gamliel said: Do not mock the law, for it is one of the three legs of the world. Why? For the sages taught, (Pirkei Avot 1:18) "On three things the world stands: On law, on truth, and on peace." Pay attention that if you pervert the law, you have shocked the world, for it is one of its legs. Our rabbis say: The power of the law is fierce, for it is one of the legs of the Chair of Glory. How do we know? (Psalms 89:15) "Righteousness and justice are the foundation of your throne; love and faithfulness go before you." The Holy One, blessed be He, says: Since the punishment of the law is fierce, be careful. From where do we know this? From that which we read on the subject, (Deuteronomy 16:18) "Judges and officer

9) If in the end all Jews are included (for inspection), why is it written "of his sons, the Cohanim"? To teach that the pronouncement of "tumah" and "taharah" must be made by a Cohein. How is this effected? An Israelite sage inspects the plague-spots and says to the Cohein, even if he himself is unversed (in their inspection): Say "tamei," and he says "tamei"; say "tahor," and he says "tahor." Variantly: What is the intent of "or to one of his sons, the Cohanim"? Because it is written (Devarim 21:5): "And by their word (that of the Cohanim) shall every contention and every plague-spot be (ruled upon)" — Contentions are hereby compared to plague-spots. Just as plague-spots are adjudicated in the daytime, so, contentions are to be adjudicated in the daytime.

And when you approach the battle, the priest shall come forward and address the people (Deuteronomy 20:2): And so [too] does it state (Deuteronomy 21:5) "The priests, the Sons of Levi, shall come forward." And [regarding] anyone who serves the king, when the king makes a decree, he carries out his decree. And the Levites serve the Holy One, blessed be He, and carry out His decrees. "Be strong and resolute, be not in fear or in dread in front of them" (Deuteronomy 31:6). And why? "For the Lord your God Himself marches with you; He will not fail you or forsake you." He does not leave you, and He goes forth in front of you and makes war. And so Deborah says to Barak, "Rise, this is the day on which the Lord will deliver Sisera into your hands; is not the Lord going forth before you" (Judges 4:14). But Barak said to her (Judges 4:8), "If you go with me, I shall go." [So] she said to him, "Do you need me, 'is not the Lord going forth before you?'" [In the case of] a king of flesh and blood, his servants and his troops go forth to war and he is behind them. But the Holy One, blessed be He, is not like this, but rather He is first. And so is it written with David (II Samuel 5:23-24), "Do not go up, etc. but confront them at the baca trees. And when you hear the sound of marching in the tops of the baca trees, then go into action." As they are full of thorns. And why did the Holy One, blessed be He, reveal himself from the tops of the baca trees? Because Israel was in distress. Rabbi Berakhia said, "This is that which is stated, 'I am with him in distress'" (Psalms 91:15). "For the Lord will be going in front of you to attack within the Philistine camp." Hence, "For the Lord your God Himself marches with you." And in the world to come, "Then the Lord will come forth and make war on those nations as He is wont to make war on a day of battle" (Zechariah 14:3). So did Rabbi Tanchuma bar Abba expound.