The Book of Mormon contains the voices from those that are in the dust. "And they shall cry from the dust." From the Plates of Brass, Lehi would have known the words of Isaiah 29:4, "And they speech shall be low out of the dust." The testimony of the dead lives, and that testimony is that Jesus is the Christ, that He has risen from the grave, and that He is the only begotten Son of God.
Jeff Lindsay, "’Arise from the Dust’: Insights from Dust-Related Themes in the Book of Mormon (Part 1: Tracks from the Book of Moses)," Interpreter: A Journal of Latter-day Saint Faith and Scholarship 22 (2016): 179–232.