In this chapter, Solomon brings the ark of the covenant into the new temple.
This chapter is largely copied from 1 Kings 8, which follows the pattern of the earlier chapters in 2 Chronicles that were also mostly duplicated from 1 Kings. There are a few things I would like to discuss, and I will begin with the differences between here and 1 Kings 8. There's only one big difference I can see between 1 Kings 8 and the present chapter, and that is verses 11-13 which references the priestly divisions and the musicians. This is unique to Chronicles because the book of Kings does not discuss the priestly divisions or assignment of musicians at all. Both of these were part of David's preparations in 1 Chronicles 24 and 25. I don't think this is an important difference, but it does show that Chronicles was written as a single consistent unit.
Next, I would like to briefly address how this chapter fits into Chronicle's main theme. This chapter is basically the crowning moment in the construction of the temple. Even though the temple narrative will go on for two more chapters, this is the first moment when we could say that the temple is "finished". Having constructed the building and filled it with the lampstands, tables, altars and everything else that was prescribed in the Law of Moses, we have now reached the point when the ark of the covenant can be brought in, symbolizing the LORD's presence coming to dwell in the temple. We see God's presence fill the temple in an even more tangible way in verse 13-14 when the glory of the LORD filled the temple like a physical cloud.
This is a very important part of the story because it shows the LORD's approval of the temple. To the Chronicler, the LORD's approval is absolutely essential because without it, the temple would not have any unifying power to the nation of Israel in his own time. Everything that I said in the introduction hinges on God accepting them and being the center focal point for their nation's reconstruction.
There are a few more details I would like to pick out. In verse 2, it says that Solomon is bringing up the ark of the covenant from Zion, the city of David. He is bringing it to the temple, which is in Jerusalem. In many other places, Zion or "the city of David" are used to refer to Jerusalem, but from this verse we can see they are actually distinct locations. It's most likely that Zion is a district or suburb of Jerusalem. The distinction between them has faded over time, but at the time this passage was written they were still known to be separate.
In verse 5, it says that the Levites bring the ark and the tent of meeting up to the temple. This is a little confusing because it's not entirely clear what "the tent of meeting" is referring to. For instance, there is the tabernacle of Moses that is at Gibeon, but the ark of the covenant is already in Zion, and it was placed in "David's tent", i.e. a separate tent that David placed to hold the ark while the temple was still being planned and built. Since this chapter is so heavily focused on the ark of the covenant, my first guess is that the "tent of meeting" refers to David's tent which would have been located with the ark, but my NIV commentary suggests that the "tent of meeting" is actually the tabernacle of Moses being removed from Gibeon.
Verse 9 says something very interesting: "and they are still there to this day". Since we know for sure that the temple was destroyed by the Babylonians and the book of Chronicles was written after that, this verse is almost certainly copying verbatim from an earlier text that predates the temple's destruction. Otherwise, the poles would not have "still been there" for the Chronicler to write about. This verse is almost directly copied from 1 Kings 8:8, but even 1 Kings was finalized after the destruction of Jerusalem so it is probable that 1 Kings 8:8 is also copying from some earlier unnamed source.
In verse 10, it says that only the two tablets were kept in the ark, which probably means that the jar of manna and the staff of Aaron (also placed there during the lifetime of Moses) were probably lost or destroyed by the time the temple was built. These items were placed in the ark way back in Exodus 16:32-34 and Numbers 17:10-11. We are never told that they are removed, and in fact these items almost entirely disappear from the biblical record immediately after they are created. Since they have disappeared by this time, it's likely that the jar and staff were destroyed by the Philistines or some other hostile nation during the Judges period.
Finally, in verses 13-14, God's glory comes down and fills the temple with a cloud, which mimicks the dedication of the tabernacle of Moses in Exodus 40:34-35. This is yet another parallel between the tabernacle and the temple, both in terms of their respective designs but also in the narrative that describes their construction and dedication.
In the next chapter, Solomon completes the dedication of the temple with a prayer.