Contradiction with 2 Samuel 24:1
In 1 Chronicles 21:20, the act of numbering Israel is attributed to Satan inciting David, while in 2 Samuel 24:1, it is the anger of the LORD that moves David to number Israel, suggesting differing sources of provocation.
2 Samuel 24:1: And again the anger of the LORD was kindled against Israel, and he moved David against them to say, Go, number Israel and Judah.