2 Nephi Chapter 27
See also Why did Nephi Include the Writings of Isaiah in his Records?
Summary: Nephi includes these writing from Isaiah where he talks about the restoration of the Gopsel to the earth. In verse six, he talks about the coming forth of a book (The Book of Mormon) and that three witnesses will testify of the book. He then states it will be a "marvelous work and a wonder."
Key Scriptures (italicized and in quotes):
6 And it shall come to pass that the Lord God shall bring forth unto you the words of a book, and they shall be the words of them which have slumbered.
12 Wherefore, at that day when the book shall be delivered unto the man of whom I have spoken, 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, besides him to whom the book shall be delivered; and they shall testify to the truth of the book and the things therein.
26 Therefore, I will proceed to do a marvelous work among this people, yea, a marvelous work and a wonder, for the wisdom of their wise and learned shall perish, and the understanding of their prudent shall be hid.