What is the meaning of the phrase “the priests the Levites” (הַכֹּהֲנִים הַלְוִיִּם)?

Question

In Deu. 17:9, it is written,

⁹ “And you shall come to the priests, the Levites, and to the judge there in those days, and inquire of them; they shall pronounce upon you the sentence of judgment. ^{NKJV, 1982}

^ט וּבָאתָ אֶל הַכֹּהֲנִים הַלְוִיִּם וְאֶל הַשֹּׁפֵט אֲשֶׁר יִהְיֶה בַּיָּמִים הָהֵם וְדָרַשְׁתָּ וְהִגִּידוּ לְךָ אֵת דְּבַר הַמִּשְׁפָּט

Other English versison translate it as “the priests the Levites” (no comma; ASV, KJV) and “the Levitical priests” (NET, NIV, NLT).

Assuming that all those who could minister as priests were Levites—specifically, the sons of Aaron (who was the great-grandson of Levi), why does the scripture include הַלְוִיִּם (“the Levites”) after “the priests”? It seems superfluous.

Answer 1

I believe that הַלְוִיִּם is in adjectival form, so that the phrase translated in English would be something like "Levitical priests". This is how the JPS Tanakh translates it, as well as how Rashi explains it (in English translation):

[And you shall come to] the Levitic kohanim: i.e., the kohanim, who are descended from the tribe of Levi.

and to the judge who will be in those days ...

So the verse seems to be referring to two entities: the Levitical priests (KJV: the priests the Levites) and the judge.

The Septuagint translation reflects this understanding as well, I think:

καὶ ἐλεύσῃ πρὸς τοὺς ἱερεῖς τοὺς Λευίτας [-] καὶ [-] πρὸς τὸν κριτήν, ὃς ἂν γένηται ἐν ταῖς ἡμέραις ἐκείναις, καὶ ἐκζητήσαντες ἀναγγελοῦσίν σοι τὴν κρίσιν.

I agree the English translations are confusing (of the LXX as well as of the MT). Whether they read "the priests the Levites" or "the priests, the Levites", though, I think the right understanding is something like, "the priests, [that is] the Levites, ..."

Answer 2

You have a distinction in Torah of High priests or singular Kohen and plural koheniym as the descendents of Aaron. Then the other priests or really Tabernacle or Temple workers from the Tribe of Levi which carried out all the other duties. After king David's time the two sons of Zadok produced twenty four sons. These became the Zadokites or old Saducees. So even if all Levites are priests all Levites are not koheniym or high priestly families. Most of scripture is written by this Tribe. Moses, Jeremiah, Ezekiel, Ezra and of course Matthew, Mark, to name but a few.