Poetry by Joseph Smith? That is certainly not what Joseph Smith is known for, nor is it often claimed that he was a poet in all the writing and studies made about him. [Orson F. Whitney is the exception that comes to mind.] But the following poem, when published in 1843, carried his byline when it was published. As a paraphrase of D&C 76, this poem fits well, I think with the Gospel Doctrine Book of Mormon lesson #41. As Christ teaches to the Nephites in this lesson (3 Nephi 22-26) he focuses on making sure that their scriptural cannon is complete, adding the neglected prophecies of Samuel the Lamanite and the to them unknown teachings of Malachi. And then he expounds all things unto them. Doesn’t section 76 have that kind of “exposition of all things” feel to it?
Scripture is often repeated in scripture, and poets have rarely been shy about re-using lines of poetry, often without attribution. Plagiarism is everywhere, and our view of it as a faux pas is really relatively recent—this view is certainly more recent than the mid 19th century, when Mormon newspapers started churning out poetry and other forms of Mormon literature. The 9th Book of Mormon lesson is also about repeated scripture, specifically Nephi’s use of the early chapters of Isaiah which seem to make up the bulk of 2nd Nephi. Perhaps Nephi served as an example for the poetry I’ve chosen for this lesson.