The book of Jude contains a prophecy from Enoch which Joseph Smith was aware of. Jeffrey M. Bradshaw explains the significance:
Note that since Joseph Smith was aware that the biblical book of Jude quotes Enoch — more specifically 1 Enoch itself — the most obvious thing he could have done to bolster his case for the authenticity of the book of Moses (if he were a conscious deceiver) would have been to include the relevant verses from Jude somewhere within his revelations on Enoch. But this the Prophet did not do.– Jeffrey M. Bradshaw – An Old Testament KnoWhy for Gospel Doctrine Lesson 5: “If Thou Doest Well, Thou Shalt Be Accepted” (Moses 5-7) (JBOTL05C)
Why would Joseph Smith not include the Jude verses in the Book of Moses? Couldn’t he have pointed to it as proof of the Book of Moses?