ציטירנדיקער פּירוש אויף עזרא 7:24

And this shall be the judgment of the priests, etc. Most commentators have struggled to find a connection between this section and the preceding section, and they have not found a sufficient explanation. See the book of Abarbanel, which brings many opinions on this matter. I say that since it is stated This will be the manner of the king who will reign over you, etc., and he will take your fields and your vineyards, etc. (First Samuel 8:11–14), the word over you indicates that the judgment of the king and his actions are already hinted at in the Torah, as it is written, You shall surely set over yourself a king. That He will rule over you in your person, and all the more so over your possessions. Therefore, the section about the king, whose judgment is to take everything by force, is juxtaposed with the section about the priests, whose judgment is not so, but rather they take their wages for their service, as it is written, to stand to serve, etc. This is not as Korah claimed, that they take in a domineering manner like a king, as explained in its place. And it is possible that this hints to the king not to touch anything that the priests have received from the Divine table, and toll, tax, and land-tax, one is not permitted to impose upon them (Ezra 7:24).

NOR A SPADE WITH WHICH TO DIG. Rav: it is forbidden to take money for teaching Torah, as the verse says “and G-d commanded at that moment to teach you laws and statutes” (Deuteronomy 4:14), and another verse earlier¹⁵⁰Tosafot Yom Tov clarifies that these are two separate verses that Rav wrote as one. says “...as Hashem my G-d commanded me” (Deuteronomy 4:5)—just as I learnt for free, you must learn for free. This is based on the Talmud in Nedarim 37a, where Ran writes (s.v. uchtiv re’eh): “As He commanded me.” I.e. he commanded me to teach for free. Otherwise, to what could “as He commanded me” be referring to? We cannot say that it means “[as He commanded me] to teach for pay”, for how could Moses say “as he commanded me”—had G-d commanded him this? Is it impossible to teach without taking pay? We also cannot say that he meant G-d commanded him these things and they were not of his own invention, for the people certainly would not have entertained such doubts, as the verse says “they will believe in you forever” (Exodus 19:9). We must say, rather, that “as He commanded me” must mean that He commanded me to teach for free.
Rav also writes: similarly, a judge may not take money for rendering judgment… and if [he does], his rulings are void. This is a mishna in Bechorot 4:6, see our comments there.
Rav also writes: the Torah has allowed him to benefit… in that his merchandise should be sold in the market first, and that the first customers in the market be directed to him.¹⁵¹Our editions of Rav do not have this second benefit, but Rambam includes it in his commentary on the mishna, which is Rav’s source. Rambam in his commentary here: ...for merchants regularly honor one another by doing these two things, even though there is no learning among them. A Torah scholar is not worse than a respected ignoramus.
Rav also writes: he is also exempt from all taxes and burdens. This is based on a verse in Ezra 7:24: “We also declare to you that it is unlawful to levy minda, b’lo, and halach¹⁵²Types of taxes. on all the priests and Levites, singers and gatekeeprs, Nethinim and whoever serves in this Temple of God.”

As is found in Ezra 7:24, "all priests, etc. the king's tax, the poll tax and the meal tax, no one is empowered to place upon them."