1 Nephi 19:10

In verse 10, we find that Nephi is talking about the life of Jesus Christ nearly 600 years before it happened. A great thing about this verse is that he mentions stories from, what we can assume, the brass plates. As a testimony of who He is and what He has done, Nephi begins by saying that Jesus is the God of our fathers. He led the Israelites out of Egypt and kept them alive as they wandered in the wilderness. He is the same God of Abraham, Isaac, and Jacob. He will come down to the earth live among men and yield himself, according to the words of the angel. I'm assuming that Nephi is referring to the vision he had hosted by an angel (see 1 Nephi 11:32). So, he will give (gave) himself to the traitors and be judged of the people. A prophet named Zenock prophesied that he would be lifted up, and Neum (most likely the Nehum from the Old Testament) said that he was going to be crucified. Zenos, another prophet said that Jesus was then going to be buried in a sepulchre. He also prophesied that there will be three days of darkness on the isles of the sea when Christ dies, which will be given as a sign of His death. A sign more especially for the house of Isreal. This is interesting the "more especially...", because it could mean that there were others on the isles of the sea that might not have been of the house of Israel, who saw the sign. However, we know that the Nephites and Lamanites were of the house of Israel and those that did not die, saw the sign of the three days of darkness (see 3 Nephi 8:20-23).

We can see that Jesus Christ did come to do many things and one was to fulfill all that He caused to be written about His life on earth by the ancient prophets (e.g., Matthew 1:21-23).

So, what about these prophets? In the past, I have thought about these references to scriptures that we do not have. Here is a good entry for Lost Books in the Bible Dictionary that explains some of this. We can also find a little more from the entries of Zenock, Zenos, and Neum from the Index of the Book of Mormon. Here is another interesting article about these men among others.