Some people might wonder why, in blessing his son Sam, Lehi said that Sam's seed would be numbered with Nephi's seed (see 2 Nephi 4:11). Put another way, Why was Sam's portion of inheritance linked with that of Nephi? There were "Nephites," "Jacobites" and "Josephites" (see Jacob 1:13; 4 Nephi 1:38; Mormon 1:8), so, Why were there no "Samites"?
According to John Welch, interwoven with the ancient Near Eastern principles of family law were fairly specific laws of inheritance and succession (de Vaux 1:53-55; Elon 434-35, 446-64; Falk 165-70). Preserving and transmitting the family estate from one generation to the next was a fundamental and essential aspect of ancient society and economy. Typically, upon the death of the father, the eldest son of the father's first wife was entitled to occupy the father's house and estate, and legal provisions were established in the early law codes to prevent the father from wrongfully favoring younger sons or the sons of wives with lesser status (Falk 165-70)
In early Israel several cases of succession ran contrary to the common custom. There, "a father was free to choose a younger son as his successor, if he found the eldest unworthy of the office" (Falk 165). In that community, more than property was at stake. The tribal structure of early Israelite society required that a leader be chosen to take the father's place as both the secular and spiritual leader of the clan. This power "did not pass automatically, but had to be conferred by the father in a special blessing" (Falk 165). This was accomplished by a formal public "acknowledgement" of that son by his father (Deuteronomy 21:17), usually in the form of an oral blessing (EJ 6:1306-11).
The accounts in Genesis are remarkable in that younger sons are frequently preferred over their elder brothers (see the stories of Abel, Seth, Jacob, Ephraim, David and Solomon), and in that fathers sometimes separated the privileges of property inheritance from those of political and priestly rights (somewhat as Lehi also does in giving priestly duties to Jacob). Thus, Jacob of old blessed Judah with the rights of governance (Genesis 49:10), and Joseph with a double portion of the birthright through Ephraim and Manasseh (Genesis 48:22), and Levi eventually became entitled to certain inherited rights of the priesthood.
As time progressed, the laws in Israel changed, particularly to clarify and protect the property rights of the firstborn son. For example, he was virtually guaranteed a double share as compared with his brothers. . . . So how was Lehi to deal with these expectations of the firstborn Laman and at the same time leave Nephi in a secure position as the "ruler and teacher" (1 Nephi 2:22; 3:29) he was chosen by God to become? . . .
Concerning the rights of primogeniture and leadership, Lehi said to Laman, Lemuel, Sam and the sons of Ishmael, "If ye will hearken unto the voice of Nephi . . . I leave unto you a blessing," including "my first blessing." But if they would not hearken unto Nephi, Lehi provided that their disobedience would revoke the "first blessing" and also the general blessing, and all this should then rest upon Nephi (2 Nephi 1:28-29). In other words, Lehi was willing to give Laman the titular blessing so long as the group in substance followed Nephi.
To whatever extent Lehi acknowledged Laman's right to the double portion of the firstborn, he simultaneously did three things that appear to have been calculated to detract from Laman's firstborn double portion rights.
First, he combined Sam's inheritance and seed with Nephi's (2 Nephi 4:11). As Jacob in the patriarchal period had effectively doubled the blessing of Joseph by granting equal blessings to Joseph's two sons Ephraim and Manasseh (Genesis 48:22), so Lehi effectively doubled Nephi's position by granting a share of the land to Sam and then merging it with Nephi's
Second, he blessed his firstborn's children to the effect that their sins and cursings would be answered upon the heads of their parents (2 Nephi 4:5-9). This could not have been flattering to Laman.
Third, Lehi referred to Jacob three times as his "firstborn . . . in the wilderness" (2 Nephi 2:1,2,11), and singled him out to spend his life "in the service of thy God" (2 Nephi 2:3)--a role often associated with the position of a firstborn son. These steps diminished the uniqueness and importance of Laman as the eldest son. [John W. Welch, "Lehi's Last Will and Testament: A Legal Approach," in The Book of Mormon: Second Nephi, the Doctrinal Structure, pp. 74-78]
Thus, John Welch has provided a plausible cultural background and answer as to why there were no "Samites." His words also give testimony to the fact that the ancient world of which Lehi and Nephi were proposed to be a part of in the pages of the Book of Mormon was a very real world.