In chapter 8, Nephi records a significant vision, filled with symbolism, that his father, Lehi, had. This is the most detailed vision account of the Book of Mormon and therefore we should treat it as significant, not only because it is so detailed but because of the many teachings and doctrines that are packed into it.
As you read 1 Nephi 8 and have questions about what each of the symbols in the vision represent, be sure to keep a thumb in 1 Nephi 11 and 1 Nephi 15 which each give a more detailed interpretation. As I describe Lehi's vision, I will link to the cross references for each interpreted element as found in these later chapters to make it easier to correlate them together. Stay tuned, though, because when we get to the later chapters, I'll go into more detail about what these symbols stand for, especially what they can be compared to in our day.
Lehi begins the account of his dream or vision by stating that it is both a reason to rejoice (because of the righteousness of Sam and Nephi) and a reason to warn (because of the rebellious behaviors of Laman and Lemuel).
First, Lehi relates that he saw a man dressed in white who invited Lehi to follow him. Lehi soon finds himself in a "dark and dreary waste" and prays to be delivered from it. After this prayer, he sees a "large and spacious field" and in the middle of it is "a tree, whose fruit was desirable to make one happy".
Lehi eats some of the fruit and finds it is "most sweet, above all that I ever before tasted." It is so delicious, in fact, that he immediately feels a desire to share it with his entire family. He looks around for them and finds that there is a river of water that runs alongside the tree. Trying to find the river's source, he looks and sees that the head of it is a little way off and sees Sariah, Sam, and Nephi standing there as if they don't know where to go.
Lehi motions and calls to them to come to him, and they do. Then, looking also for Laman and Lemuel, he finds them but they refuse to come and partake of the fruit.
Next, Lehi sees a "rod of iron" that "extended along the bank of the river and led to the tree". Next to the rod of iron was a "strait and narrow" path leading up to the tree from the head of the fountain and out into a large and spacious field "as if it had been a world".
On the path were a great number of people who were also trying to get to the tree, as well as a mist of darkness covering the path in places. Some caught hold of the iron rod, successfully arrived at the tree, partook, and invited others to eat. But, upon eating, they looked around "as if they were ashamed".
Lehi then noticed that there was a "great and spacious building" that seemed to stand in the air. The people inside the building were of all ages and types, wearing very nice clothing, and pointing their fingers in derision and an attitude of mocking towards those who had taken the fruit. Those who became ashamed for eating the fruit "fell away into forbidden paths and were lost".
Lehi saw people grasping the iron rod and arriving at the tree to eat the fruit. Others let go of the iron rod before arriving at the tree, fell away from the path and the rod, and fell into a river of filthy water.
There were a great number who did not grab hold of the rod at all, but were "feeling their way towards that great and spacious building", going inside, and imitating the others in the building by pointing their fingers in scorn at those taking the fruit. But those who were eating of the fruit "heeded them not", or refused to pay any attention to them. Those who did pay attention to them fell away.
Laman and Lemuel never did partake of the fruit in Lehi's dream, so Lehi feared for them "lest they should be cast off from the presence of the Lord". Lehi invited them to repent "with all the feeling of a tender parent".