According to Hugh Nibley, a quotation from an Enoch text, discovered in 1888 (58 years after the Book of Mormon was published), occurs in the thirteenth chapter of Helaman. In the Enoch text, Enoch says:
Ye have not remembered the Lord in the days he gave you your riches; ye have gone astray that your riches shall not remain, because you have done evil in everything. Cursed are you and cursed are your riches.
In Helaman 13, Samuel the Lamanite is speaking to the wicked Nephites. He had access to the plates of brass and other records. He says the following:
O ye wicked and ye perverse generation … behold, the time cometh that he curseth your riches … And then shall ye lament and say … O that we had remembered the Lord our God in the day that he gave us our riches, … our riches are gone from us… . they have slipped away from us, because of the curse of the land. (Helaman 13:29-35)
[Hugh Nibley, The Collected Works of Hugh Nibley, Vol. 2, p. 8]
Helaman 14:2 Behold I give unto you a sign (Illustration): Chart: “Samuel the Lamanite’s Prophecies.” [John W. & J. Gregory Welch, Charting the Book of Mormon: Visual Aids for Personal Study and Teaching, F.A.R.M.S., Chart #48]
Helaman 14:2 Behold, this will I give unto you for a sign at the time of his coming (Illustration): Chart: “The Coming of Christ to the Nephites: A Pattern for His Second Coming.” The recorded conditions that prevailed on the American continent preceding Jesus Christ’s visitation to the Nephites and Lamanites can be compared to the prophesied conditions of the world before his second coming. [John W. & J. Gregory Welch, Charting the Book of Mormon: Visual Aids for Personal Study and Teaching, F.A.R.M.S., Chart #51]