The chapter starts out saying that the anger of the Lord was kindled against Israel. (Does this just mean the northern kingdom?) Here Rashi says he doesn't know what it is about:
Then David is told to count the Jews, but then it is revealed that this is a great sin, and there is a plague on the people for doing exactly this.
In the book of Chronicles the same exact episode is described but not as God doing it. The first verse in the book of Samuel attributes it to God moving David to do it, which Rashi says "provoked".
What is going on? The first verse in the book of Samuel attributes it to God, which is very weird!