In a letter dated June 25, 1833, Joseph Smith spoke about his belief the missing stand-alone books mentioned in the Bible would not be restored as part of the Joseph Smith Translation project:
We have not found the book of Jasher nor any of
the othe[r] lost books mentioned in the bible as yet nor wille we
obtain obtain them at
present—respecting the Apochraphy [Apocrypha] the Lord Said to us that
there were many things in it which were true and ther were many things in
it which were not true and to those who desired, it should be given by the
spirit to know true from the false (Letter to Church Leaders in Jackson County, Missouri, 25 June
1833)