This is in addition to what
was written, that the Sefer referred in the
Torah Kedumah, has to be the
eighth chapter. Central in the eighth chapter is last week's Parasha, the story of Bileam. That brings to mind Baba Batra 14b, where Chazal make a surprising distinction between Moshe's own book, and Parshat Bileam. Parshat Bileam then is the eighth chapter, a separate book, and both the seven chapters, his book, and the eighth chapter, are written by "Moshe."