This chapter is about attacks on God's word from without and within. It is remarkable how as we go through a book like Nehemiah and the history of events at that time, we see the inevitable parallels between these circumstances and the circumstances of the people of God in every age.
When it's time for Reformation and improvement and going back to the right ways then all kinds of people will surface who are not happy about that at all, and people who have been in alliance with the enemies of the people of God, and that's exactly what we find here in this book.