The Lord commanded others besides the Prophet Joseph Smith to bear record of the divinity of the Book of Mormon (D&C 17; 128: 20). See the testimonies of these witnesses in the "Introduction" at the front of the Book of Mormon.

By the words of three I will establish my word, 2 Ne. 11: 3. Witnesses to bear testimony of his word unto the children of men, 2 Ne. 27: 12-13. In the mouth of three witnesses shall these things be established, Ether 5: 4. By faith the Three Witnesses shall see the plates, D&C 17.