While encamped in the Valley of Lemuel, Lehi sent his sons back to Jerusalem to obtain their own religious record — the "plates of brass" — from Laban the governor. Laban and Lehi had a shared ancestry, and the brass plates contained not only the Jewish scriptures but also Lehi's genealogy.

The brothers "cast lots" (1 Nephi 3:11) to see who should go to Laban for the plates. In Old Testament times, it was believed that the outcome of casting of lots was directed by God (see Proverbs 16:33). The lot fell on Laman.

When asked for the plates, however, Laban became angry and chased Laman away. The brothers came back again — this time with their family riches — but Laban took their riches and tried to kill the brothers, who escaped into the wilderness and hid in a "cavity of a rock" (v. 27). We now know that there are many caves in Palestine, and they were frequently used by fugitives.

Angry, Laman tried to beat Nephi with a stick but was stopped by an angel. Laman still remained unconvinced that they could obtain the plates from Laban and his "fifty" (1 Nephi 3:31).

Hugh Nibley explains that while Laban would have had tens of thousands of soldiers at his command, the regular permanent garrison in Jeruslaem would have been between 30 and 50 men. In a recently discovered letter of Lehi's contemporary Nebuchadnezzar, the king speaks of a garrison of "fifty." In Babylonia, a platoon in the army consisted of 50 men and was always called a "fifty" just as Nephi spoke of "Laban with his fifty."

Nephi went again to Laban and found Laban lying drunk in the street. The spirit of the Lord commanded Nephi to slay Laban so that he could obtain the plates. At first Nephi hesitated — he had never killed a man before. Again the spirit commanded Nephi to slay Laban. Finally obeying, Nephi decapitated Laban with his own sword (see 1 Nephi 4:11-18).

While modern Americans express concern over Laban's execution, in light of Near Eastern thought Nephi's actions are not unusual. Nibley recalls the reaction to the story by a class of several Arab students. After hearing about Lehi's decapitation, one Arab student asked, "Why did this Nephi wait so long?"

John Welch argues that in light of ancient Jewish law, Nephi was not guilty of murder.

"When analyzed in terms of ancient biblical law, the case is framed within the appropriate set of legal terms and issues. This is not to say that the slaying of Laban presents us as modern readers with an easy case: neither was it an easy case for Nephi. In its ancient legal context, however, the slaying of Laban makes sense, both legally and religiously, as an unpremeditated, undesired, divinely excusable, and justifiable killing — something very different from what people today normally think of as criminal homicide."

LDS researcher Steven Olsen points out that Nephi intentionally uses the word "deliver" to emphasize the moral point of the story.

The angel who intervened with Nephi's beating said that the Lord would "deliver Laban" into their hands (3:29). Before going to find Laban, Nephi told his brothers that "The Lord is able to deliver us" and destroy Laban as he had delivered Moses and the Israelites (4:3). When Nephi hesitated in beheading Laban, the spirit told him that, as promised, the "Lord hath delivered (Laban) into thy hands" and that it was "better that one man should perish than that a nation should dwindle and perish in unbelief" (4:12-13).

"At this point," writes Olsen, "the mission to recover the brass plates is no longer simply about the temporal deliverance of a nuclear family," but "has become the spiritual deliverance of a divinely chosen nation."

Remembering how the Lord had promised to lead the Lehites to the promised land and that they could not keep the law without the scriptures, Nephi realized that the Lord had "delivered Laban into my hands" (4:17), so he slew him.

Donning the governor's robes, Nephi went to the treasury disguised as Laban, where he tricked Laban's servant, Zoram, into acquiring the brass plates. When Zoram discovered that Nephi was not Laban, Nephi gripped Zoram firmly and swore into his ear, "as the Lord liveth, and as I live" that he would spare Zoram's life if he would only listen (1 Nephi 4:32). Zoram followed Nephi without further problems.

Among the desert people, oaths are considered sacred. The most binding oaths were those sworn by the life of something. Nibley explains that "The only oath more awful than 'by my life' or (less commonly) 'by the life of my head,' is … 'by the life of God,' or 'as the Lord liveth.'"