“But behold, it shall come to pass that the Lord God shall say unto him to whom he shall deliver the book: Take these words which are not sealed and deliver them to another, that he may show them unto the learned, saying: Read this, I pray thee. And the learned shall say: Bring hither the book, and I will read them.”
2 Nephi 27:15
"In the mouth of three witnesses shall these things be established."
“The book shall be hid from the eyes of the world, that the eyes of none shall behold it save it be that three witnesses shall behold it, by the power of God … And there is none other which shall view it, save it be a few according to the will of God”
2 Nephi 27:12–13
“And now I, Nephi, write more of the words of Isaiah … for he verily saw my Redeemer, even as I have seen him. And my brother, Jacob, also has seen him as I have seen him; wherefore, I will send their words forth unto my children to prove unto them that my words are true. Wherefore, by the words of three, God hath said, I will establish my word. Nevertheless, God sendeth more witnesses, and he proveth all his words”
2 Nephi 11:2-3