“Born in the Wilderness”

After finishing with his blessing to Jacob (that was also address to all of his sons) Lehi turns to Joseph to supply him with a blessing. Little is known of the circumstances of Joseph's birth, other than that it occurred during the long journey to the Old World Bountiful and that Joseph is younger than Jacob (1 Nephi 18:7). The timing of the births in that period of travel, and the necessity of having them old enough to weather a sea journey makes me suspicious that they might have been twins, with Jacob being the first born of the two.

The multiple birth might also explain something of the naming of the two. Both of these sons were born after the retrieval of the brass plates. Remember the significance of the plates to Lehi:

1 Nephi 5:14 And it came to pass that my father, Lehi, also found upon the plates of brass a genealogy of his fathers; wherefore he knew that he was a descendant of Joseph; yea, even that Joseph who was the son of Jacob, who was sold into Egypt, and who was preserved by the hand of the Lord, that he might preserve his father, Jacob, and all his household from perishing with famine. 15 And they were also led out of captivity and out of the land of Egypt, by that same God who had preserved them. 16 And thus my father, Lehi, did discover the genealogy of his fathers. And Laban also was a descendant of Joseph, wherefore he and his fathers had kept the records. 17 And now when my father saw all these things, he was filled with the Spirit, and began to prophesy concerning his seed--

Clearly the discovery of Lehi's ancestry was a transcendental event for him. In the course of the discovery of his roots, Lehi is also inspired to prophecy about his progeny. In this event, past and future became tied together, and the impression of his lineage must have been indelibly pressed into Lehi's consciousness.

When Lehi had sons born after this instance, it is no surprise, then that he would name them Jacob and Joseph, for the two important names in his lineage. Of course had they been born a year apart, he might also have used those names, but I suggest that the promises made through the lineage of Joseph were so strong that Lehi would have used that name first, unless he knew that there was a second son who could receive that name. At Lehi's age and circumstances, this is best answered if the two were twins.