Stick of Ephraim
The Book of Mormon. This identification is based on a misinterpretation of Ezekiel 37:15-19. Mormons identify the stick of Ephraim with the Book of Mormon because it supposedly is the history of Ephraim in the new world (see D&C 27:5). The Ezekiel passage, and the LDS interpretation of it, is one of the first things Mormons learn.