I’m going to get my academic write-up out of the way right now, but I’ll be doing some academic reading this afternoon. On pages 90-92 of The Ideology of the Book of Chronicles and Its Place in Biblical Thought, Sara Japhet says the following:
Although not found in the source material in Samuel-Kings, the choosing of the Levites is mentioned twice in Chronicles:
(a.) 1 Chr 15:2: “for the LORD chose them to carry the ark of the LORD and to minister to him for ever.”
(b.) 2 Chr 29:11: “the LORD has chosen you to stand in his presence, to minister to him, and to be his ministers and burn incense to him.”
The meaning of “Levites” in these passages and in Chronicles as a whole is a controversial issue. Is the word used in a narrow sense, referring only to the non-priestly members of the tribe of Levi, or in its broader meaning, denoting all members of the tribe, including priests? It seems to me that the two meanings appear side by side in Chronicles and can only be distinguished in context. The above verses are related to, although not an exact quotation of, Deut 10:8: “At that time the LORD set apart the tribe of Levi to carry the ark of the covenant of the LORD, to stand before the LORD to minister to him and to bless in his name, to this day”…In 1 Chr 23:13, “set apart” describes the selection of the priests alone: “Aaron was set apart, he and his sons, forever, to be consecrated as most holy, to make burnt offerings to the LORD and serve Him and pronounce blessings in his name forever” (NJPS).
Many biblical scholars agree that the priestly writings and Deuteronomy present different opinions on the division of responsibilities within the Levitical priesthood. The priestly writings distinguish between the responsibilities of the sons of Aaron and the other Levites: the sons of Aaron offer the sacrifices, whereas the other Levites transport the holy objects, guard the Tabernacle, and do grunt work (see Numbers 3, 8). Deuteronomy, by contrast, does not distinguish between the responsibilities of the sons of Aaron and the other Levites: it just refers to “Levites,” as if they do all the work—sacrifices, grunt, transportation of holy objects, etc.
Why this diversity? I’m not familiar with every single explanation for this in the world of biblical scholarship, but one view that I’ve come across is that Deuteronomy was written by Levites who weren’t sons of Aaron, so, of course, they thought that they had more privileges than the sons of Aaron were willing to grant them!
So what is the stance of the Chronicler? In I Chronicles 6:48-49, he affirms the Aaronide division of responsibility: the Aaronides do the sacrifices, whereas the Levites take care of the Tabernacle. Yet, as Japhet notes, the Chronicler also says things that resemble Deuteronomic passages: God has set apart the tribe of Levi to minister before the LORD. Perhaps the Chronicler is rereading Deuteronomy to make it jibe with the Aaronide passages. Maybe he assumes that Deuteronomy makes a blanket statement: God chose the Levites to serve the LORD. But the Aaronide writings add specificity to that blanket statement: the Levites descended from Aaron perform the sacrifices, whereas the other Levites take care of the Tabernacle.