Before leaving the Old World, Jehovah promised Lehi that he would lead them to a new land. After leaving their lands behind, they would be rewarded with a new home. The description of that new land as a land of promise has led to an inevitable association with the Israelites promised land. However, it is not clear whether or not that is a legitimate comparison.
Both the phrase “land of promise” and “promised land” occur with great frequency in Nephi’s writings, and, to a lesser extent in the rest of the Book of Mormon. They do not appear at all in the Old Testament. The phrase “land of promise” does occur in Hebrews 11:9, where it speaks of Abraham leaving his home and “sojourning in the land of promise, as in a strange country.”
Tradition promises the land that Abraham was given as an inheritance for his descendants, but it was never an entire continent, never an entire hemisphere, never more than a relatively small section of land. Thus, when we read the Book of Mormon’s land of promise as any large expanse of territory, we are reading modern ideas backwards into the text in ways that the ancient people would never have understood.
As Lehi discusses this land of promise, it will never describe the dimensions of that land. What he will emphasize is the promise that is associated with the land. It is promised to his children forever, but upon conditions of righteousness. The Nephites, whose story exemplifies that promise of the land, eventually lose it. It was given them, but they will not keep it.