The Lord allowed Joseph Smith to have two sets of special witnesses to the Book of Mormon: (1) the three witnesses—Oliver Cowdery, David Whitmer, and Martin Harris, and (2) the eight witnesses—Christian Whitmer, Jacob Whitmer, Peter Whitmer, Jr., John Whitmer, Hiram Page, Joseph Smith, Sen., Hyrum Smith, Samuel H. Smith.
In 2 Nephi 27:12 the three persons who should behold the record “by the power of God” evidently are the three special witnesses. In their testimony they declared they had seen an angel, had heard the voice of the Lord, and had been shown the plates “by the power of God, and not of man.”
In 2 Nephi 27:13, the few other witnesses who should view the record “according to the will of God, to bear testimony of his word unto the children of men” evidently include the eight special witnesses.
(For further information on this topic, see the section on the witnesses in the first chapter, “The Story of the Coming Forth of the Book of Mormon.”)