The best commentary on this section is early Church history. In June, 1829, the translation of the Book of Mormon had been finished. Martin Harris had been promised, on condition of obedient faith, the privilege of being one of the three witnesses mentioned in this paragraph, as in Ether 5:1-4 D. and C.see 5). Oliver Cowdery and David Whitmer, naturally, hoped to be the other two.
The translation finished, Joseph invited his parents to come to him for a visit. They gladly came. Martin Harris accompanied them. The evening of the day on which they arrived at the home of the Whitmers, was spent in reading portions of the translation. Shortly before the manifestation the Prophet and his three friends, in answer to fervent prayers, received the revelation in the D. and C. sec. 17, in which the Lord instructed them to have faith, and, after they had seen the plates, to testify thereof to the world, “that my servant Joseph Smith, Jr., may not be destroyed, that I may bring about my righteous purposes unto the children of men in this work.” When the day came, Joseph Smith, Oliver Cowdery, David Whitmer and Martin Harris went out into the woods to engage in prayer. While they were so engaged, a heavenly messenger appeared, to Joseph Smith, Oliver Cowdery and David Whitmer and showed them the plates, and gave them this assurance: “These plates have been revealed by the power of God, and they have been translated by the power of God. The translation of them which you have seen is correct, and I command you to bear record of what you now see here.”
Martin Harris, who had left his companions for private prayer, now was joined by the Prophet, and while the two were praying, the heavenly messenger again appeared with the volume and turned the leaves, whereupon Martin Harris arose and full of joy exclaimed: “ ’Tis enough! ’Tis enough! Hosannah!”
On some other occasion, before the plates had been finally delivered to the heavenly messenger, the Prophet Joseph had shown them to Christian, Jacob, Peter, Jr. and John Whitmer, Hiram Page, Joseph Smith, Sr., Hyrum and Samuel Smith, and they had handled as many plates as he had translated, and examined the engravings. They so testify.
There are those who tell us that all this is deceit. What is their supposition? They pretend to believe—and they expect the rest of us to believe—that the Prophet Joseph, knowing that he had fabricated a story of three witnesses, succeeded in persuading his friends, in their full senses, that they were, actually and really, those three fictitious characters, and that they retained that conviction until death silenced their lips. Can any sane person believe that? Can anyone believe that it would have been possible for Cervantes to persuade one of his associates that he was actually Don Quixote, and another that he was Sancho Panza? If not, why should we suppose that the Prophet Joseph might have convinced Oliver Cowdery, David Whitmer, and Martin Harris that they were three persons existing nowhere except in the imagination of the prophet? (For a detailed account of the witnesses, see Essent. of Church Hist., Joseph Fielding Smith, pp. 72-81.)