So Jeremiah wrote in a book all the evil that should come upon Babylon, even all these words that are written against Babylon. Wrote in a book - Whether this book contained any more than is recorded in this place we do not know; probably it contained no more than what is found in Jeremiah 51:62-64. A book, ספר sepher, signifies, in Hebrew, any writing, great or small.
Related Commentaries of Jeremiah 51:60
Jeremiah 51:60
60 So Jeremiah wrote in a book all the evil that should come upon Babylon, even all these words that are written against Babylon.