Symbolic analysis: The classic tree of life imagery has the participant partaking of some part of the tree. It is usually the fruit, but may have also been a liquid. It appears that tradition associated two elements with the Tree of Life, a solid food, and a liquid. The liquid at times was the water which flowed from the base of the tree, and at times was the liquid of the fruit. This was particularly the case in the ancient Near East where palm wine was associated with the Tree of Life.
In partaking of the fruit, Lehi is participating in the larger tradition where the benefits of the tree are received by eating the fruit. The interesting part is that the tree of life in Lehi's vision has a twist on the traditional benefit. Most of the historical myths associated with a tree of life have the fruit (liquid) imparting either renewed life or its analog, renewed health. Lehi's fruit does neither. Rather than refreshing his body, the fruit of this particular tree refreshes his soul. In this way, the symbolism passes beyond the association of the Tree of Life with physical life, and moves to the realm of spiritual life. It is in this realm that Lehi's fruit is able to fill him with "exceedingly great joy."
Narrative analysis: This part of Lehi's vision was clearly shown to Joseph Smith Sr.: " Its beautiful branches spread themselves somewhat like an umbrella, and it bore a kind of fruit, in shape much like a chestnut bur, and as white as snow, or, if possible, whiter. I gazed upon the same with considerable interest, and as I was doing so, the burs or shells commenced opening and shedding their particles, or the fruit which they contained, which was of dazzling whiteness. I drew near and began to eat of it, and I found it delicious beyond description. As I was eating, I said in my heart, 'I cannot eat this alone, I must bring my wife and children, that they may partake with me." While the beginning of the visions of Lehi and Joseph Smith, Sr were clearly based on the same archetypes and celestial revelation, the outcome of the request to have their family come and partake was clearly different. For Joseph Smith Sr. the revelation was to show him unborn members of the family who should also come. For Lehi, it showed that current members would refuse to do so.
In the economy of the Lord, there are many symbols and symbolic situations which have been repeated, but frequently with slightly different meanings. In the case of the parables of Christ, the standard interpretations (see James Talmage) are quite different in their symbolic analysis to the interpretations of the same parables by Joseph Smith, Jr. Symbols by their very nature are open to multiple interpretations.