William Homer records Harris testifying of BOM's divine translation.
William Harrison Homer, “The Last Testimony of Martin Harris,” 1925, typescript, 5, M270.1 H315ho 1875?, Church History Library
Just as surely as the sun is shining on us by day, just as surely as the breath of life sustains us, so surely do I know that Joseph Smith was a true prophet of God; so surely do I know that the Book of Mormon was divinely translated. I saw the plates, I saw the angel. I heard the voice of God. I know that the Book of Mormon is true