Jerusalemites, Levitical Responsibilities and the Family of Saul (1 Chronicles 9) February 17-18
The reference to the "book of the kings of Israel" in verse 1 is evidently not to the biblical books of Kings, as these contain no genealogies.
Expositor's comments in its introduction to this chapter: "Chapter 9 itself is sometimes assigned to the period of Persian restoration…or even equated with a list of Nehemiah's during his own time (444 B.C.), of those who lived in Jerusalem and of those who resided outside (Neh 11:3-24). But while this latter document exhibits the same order in its categories (perhaps because based on 1 Chron 9), caution is advised. Thus [as one scholar] admits: 'The two lists are not so alike as sometimes supposed...' The M[asoretic] T[ext] has about eighty-one names for Nehemiah 11 and about seventy-one for Chronicles, of which only about thirty-five are the same or nearly so. Moreover some of these have a permanent relevance, e.g., names of priestly courses (vv. 10, 12) or of genealogical ancestors (vv. 11, 16), which are not subject to change in any event."
In other words, it is not clear whether the list of people dwelling in Jerusalem in verses 3-9 predates or postdates the Babylonian Exile. Some suggest that the reason for highlighting the inhabitants of Jerusalem is to put the focus on the city of David in contrast to Saul's city of Gibeon in the previous chapter. "While both cities were important centers, God had not chosen Gibeon. But He did choose Jerusalem, not [merely] as Israel's political capital but as the location for His temple. It was in Jerusalem, where the ark [i.e., the Ark of the Covenant] rested, that God met with His people. It was Jerusalem where the priests offered sacrifices for sin. It was Jerusalem where the Levites led in worship" (Bible Reader's Companion, note on 8:1-9:44).
Jerusalem is "the apple of God's eye" (Zechariah 2:8). Beyond the focus of 1 Chronicles 9, the place had been special to God even long before the children of Israel dwelt there. Mount Moriah, the Temple Mount in Jerusalem, had been the place God sent Abraham for the test with Isaac (Genesis 22:2). Indeed, Jerusalem was the site chosen by God for the sacrifice of Jesus Christ, and it will be the city from which God will later rule the world and even the universe.
Finally, verses 35-44 present again the family of Saul, basically repeating 8:29-38—but here the purpose is to segue into the story of the tragic end of his life and reign related in the next chapter of Chronicles (which we have already read).