Initial readers of the book of Nehemiah would have been unrolling a single scroll consisting of Ezra and Nehemiah. In that understanding, the phrase in question would have signalled to readers that they were beginning a new section, one no longer dominated by Ezra (that is, Ezra 7:1–10:44) but by Nehemiah.
1 The words of Nehemiah the son of Hacaliah.Now it happened in the month of Chislev, in the twentieth year, as I was in Susa the citadel,