A REFERENCE TO THE CHURCH OF JESUS CHRIST OF LATTER-DAY SAINTS
The Book of Mormon contains two sets of joint statements, written by Joseph Smith, in which individuals attest to having seen the gold plates.
The Three Witnesses are Oliver Cowdery, David Whitmer, and Martin Harris—who mortgaged his farm to finance the first printing of the Book of Mormon. The testimony published in the Book of Mormon suggests they saw the plates through supernatural means.
And we also testify that we have seen the engravings which are upon the plates; and they have been shown unto us by the power of God, and not of man. And we declare with words of soberness, that an angel of God came down from heaven, and he brought and laid before our eyes, that we beheld and saw the plates, and the engravings thereon.
— Oliver Cowdery, David Whitmer, Martin Harris
"The Testimony of Three Witnesses"
The Book of Mormon also includes a joint statement from eight men who claim to have seen the gold plates. It’s important to note that:
Some of the witnesses of the Book of Mormon, who handled the plates and conversed with the angels of God, were afterwards left to doubt and to disbelieve that they had ever *seen an angel.
— Brigham Young
Second Mormon prophet
Such characters as McLellin, John Whitmer, David Whitmer, Oliver Cowdery, and Martin Harris, are too mean to mention; and we had liked to have forgotten them.
— Joseph Smith
In the end, whatever the witnesses saw or claimed to have seen through a vision has to be weighed against the fact that none could read Reformed Egyptian. So, even if there were plates, none of them could vouch that Joseph Smith’s Book of Mormon actually came from them.