The story is now over, the final calamity has happened: except that the story is not over. Mormon’s efforts at physical and spiritual salvation of his people have failed, but he still has a mission to perform, and he closes out his record by focusing on that purpose.
Every time that “speak somewhat” is used in the Book of Mormon text it is connection with a first person narrative. It is a qualifier that the speaker/writer places on the discourse that they are about to give. This is not just Mormon the editor speaking, but Mormon the author speaking for himself. The following message is Mormon’s intended conclusion to his text.