On multiple occasions, David Whitmer described his experience with the messenger who took the abridged plates from Harmony to Cumorah. This account used to be in the Seminary and Institute manuals for the Book of Mormon, but is no longer taught.
The Saints book, Volume 1, p. 69, inexplicably omitted this account from the narrative of David Whitmer taking Joseph and Oliver from Harmony to Fayette. Saints explains how David's fields were miraculously plowed so he could go to Harmony, as David explained to Joseph F. Smith and Orson Pratt in 1878.
Note 16 in the online edition of Saints links to the page of Joseph F. Smith's letter to John Taylor describing the trip to Fayette.
The very next page in that letter relates David Whitmer's account of Cumorah, but Saints omits that from the narrative. Here's the link to that page.
In another account, David explained that Joseph Smith said this messenger who had the plates was one of the Three Nephites. I'll post that account separately.
BTW, if you read Saints, page 70, you'll see the following dialog which combines what David actually related with a fictional identification.
The audacity of this fictional narrative is stunning. The editors of Saints adapted David's account of what the messenger told his mother, Mary Whitmer, which was fair enough. But they omitted David's account of meeting the messenger on the way to Fayette, which was how he knew it was the same messenger who met his mother.
Worse, they omit David's explanation that Joseph identified the messenger as one of the Three Nephites.
They also omit what Mary herself said; i.e., that the messenger identified himself as Brother Nephi. (We see from 3 Nephi 19:4 that Nephi was one of the twelve disciples, three of whom were allowed to tarry, as described in 3 Nephi 28.)
Instead, they insert the fictional dialog that the messenger said "My name is Moroni," which never happened. The origin of that identification is from Andrew Jenson, who assumed Mary was wrong because, in his opinion, it was Moroni who had charge of the plates.
It should be obvious to any reader familiar with Church history that David Whitmer conversed with both this messenger and Moroni. David knew they were two different individuals and he even explained that Joseph said the messenger was one of the Three Nephites.
By creating a false narrative in Saints, the editors have not only misled generations of Latter-day Saints, but have generated confusion about the nature of resurrected beings. Now we are asked to believe that an old man, 5'8" or 5'9," heavy set with a white beard and hair, wearing a brown wool suit (which fits the description of the Three Nephites, assuming they were changed around the age of 72 as their fellow disciples were promised), is the same individual as the resurrected Moroni who was glorious, wearing a white seamless robe, and taller than the average men of the time.
For a discussion, see
The same person?
David Whitmer’s description
Oliver Cowdery’s description
We were suddenly approached by a very pleasant, nice looking old man… He was I should think about 5 ft 8 or 9 inches tall and heavy set, about such a man as James there, but heavier, his face was as large, he was dressed in a suit of brown woolen clothes his hair and beard were white like bro. Pratts, but his beard was not so heavy. I also remember that he had on his back a sort of knap sack, with something in shaped like a book. It was the messenger who had the plates.
The stature of this personage was a little above the common size of men in this age; his garment was perfectly white, and had the appearance of being without seam.