The image of the iron rod is found in several passages of the Bible. It has been described as a rod used to discipline and punish the wicked, as well as a shepherd's rod to guide a flock. Though it is used in a variety of contexts in the Bible, it's use in Lehi's and Nephi's vision of the Tree of Life is mostly unique, and yet consistent with Biblical metaphors. In addition, the Lehi's and Nephi's vision bears a striking similarity to a specific passage of the Koran. The following commentary and references are meant to reveal the complexity, uniqueness, and consistency of the vision of the Tree of Life, which can be found in 1 Nephi 8 and 1 Nephi 11-14.
In the Book of Mormon, both Nephi and Lehi are given a vision in which they see a tree that bears fruit, and a rod of iron that leads along a straight path toward the tree. A mist of darkness covers the land and the only way to reach the tree and eat its fruit is to cling to the rod of iron. Those who do not hold to the rod of iron, are lost and drowned in a river. Lehi states "And I beheld a rod of iron, and it extended along the bank of the river, and led to the tree by which I stood. And I also beheld a strait and narrow path, which came along by the rod of iron, even to the tree by which I stood; and it also led by the head of the fountain, unto a large and spacious field, as if it had been a world. And I saw numberless concourses of people, many of whom were pressing forward, that they might obtain the path which led unto the tree by which I stood" (1 Nephi 8:20-21).
"I beheld the Son of God going forth among the children of men; and I saw many fall down at his feet and worship him. And it came to pass that I beheld that the rod of iron, which my father had seen, was the word of God, which led to the fountain of living waters…" (1 Nephi 11:24-25).
In the Book of Mormon vision of the tree of life we have a synthesis of two separate metaphors. Jesus Christ, who is the word of God and whose words are likened to a rod of iron, and the "cord of God" of the Koran, which is seen as saving those who hold on to it. Those in Lehi's vision, who do not grasp to the rod of iron, much like the "cord" described in the commentary of the Koran, are drowned in a river of water.