In 1 Nephi 8 we read of Lehi’s dream including the tree of life. Stephen D. Ricks explains why this is significant:
Given the Semitic background of the Book of Mormon, it is not surprising that an ancient Near Eastern symbol such as the tree of life should appear in the Book of Mormon and be supported by many other evidences from other ancient Near Eastern cultures, including Mesopotamia and Egypt. The tree of life is first mentioned in the account of Lehi’s dream, where Lehi states that “it came to pass that I beheld a tree, whose fruit was desirable to make one happy” (1 Nephi 8:10). In Nephi’s similar vision the tree of life is associated with the waters of life: “And it came to pass that I beheld that the rod of iron . . . led to the fountain of living waters, or to the tree of life; which waters are a representation of the love of God” (1 Nephi 11:25).10
Though not expressly named as such, the Semitic kiskanu-tree (like the Sumerian gis-kin) of Mesopotamia “is identical with the tree of Life.” As in the Book of Mormon, this tree of life is closely linked to the waters of life, since “the tree of Life constantly needs the Water of Life near which it is growing in the garden of paradise.” This is also reminiscent of an ancient Jewish tradition that “the tree of life is planted near the source of the water of life.”
The ancient Mesopotamian legend of the hero Gilgamesh gives further insight into the “plant of Life” that, according to Geo Widengren, is like the “tree of Life.” In the legend, Gilgamesh, exhausted from his search for the very aged Utnapishtim, who lived on an island at the edge of the world, is taken by Utnapishtim “to the washing place” in order to “wash off his grime in water clean as snow.” Gilgamesh is then clothed in “a cloak to clothe his nakedness” with a band placed on his head. Utnapishtim later tells him where to get the “plant of Life.” Gilgamesh does find the plant, but it is spirited away by a snake, thereby allowing the snake to shed its skin periodically but causing Gilgamesh to fail in his quest.
The tree of life and its connection with the waters of life also occur in ancient Egyptian religion and literature: “From the age of the Pyramid texts the word ht n ankh, ‘Tree of Life,’ appears.” There is a miniature statue of Rameses II stretched out on the leaves of the ished (i.e., persea) tree, the Egyptian tree of life. The inscription on the statue indicates that Rameses’ name was written on the leaves of the ished tree, which served as a kind of book of life or book of remembrance. The sacred tree and water are found together in many Egyptian temple complexes.– Stephen D. Ricks, “Converging Paths: Language and Cultural Notes on the Ancient Near Eastern Background of the Book of Mormon,” in Echoes and Evidences of the Book of Mormon, edited by Donald W. Parry, Daniel C. Peterson, and John W. Welch (Provo, Utah: FARMS, 2002), Chapter 12
Where would Joseph Smith be reading about all these ancient traditions such as the tree of life?