A young Nephi kills drunken Laban with Laban’s own sword only four chapters into the Book of Mormon (See 1 Nephi 4). Modern readers might stumble over any justification for killing Laban, as Nephi does at first. However, looking through the cultural context of a believing Hebrew from 600BCE sheds new light on understanding the account.
Nephi and Laban Background
By the time Nephi raises the sword to kill Laban, the two were already well acquainted (See 1 Nephi 3). Laban possessed the brass plates, a compilation of scriptures engraved into metal. The prophet Lehi, Nephi’s father, instructed his sons to obtain the brass plates as Lehi directly received commandment from the Lord.
The eldest son of Lehi, Laman, requests the plates from Laban. Laban not only denies the request, but in anger falsely accuses Laman as a robber and threatens his life. At Nephi’s suggestion, the sons collect all their valuables and offer to purchase the scriptures. This only results in the family being robbed of their silver and gold while fleeing for their lives from the city of Jerusalem.
Reviewing Laban’s Actions
Laban, a corrupt man of influence and power, takes liberties and actions directly against the scriptural commandments of his day. His actions mirror the time period. Accusations of corruption, false allegiances, immorality and idolatry flood the chapters of Biblical prophets from the era. Jeremiah gets imprisoned (see Jeremiah 32) and the prophet Urijah ben Shemaiah is unjustly killed (see Jeremiah 26:23). Laban embodies a microcosm of the corruption within Jerusalem and the family of Nephi suffer dearly.
Spirit of the Lord speaking to Nephi summarizes Laban’s actions (see 1 Nephi 4:11):
He does not obey the Lord’s commandments. [This includes bearing false witness]
He stole the family’s property.
He attempted to kill Nephi. [Additionally in the account, the other brothers as well]
Nephi Kills Laban
Laban is portrayed in the account as an unbelieving, angry, powerful, false accuser who commands the killing of four innocent brothers for personal gain. Despite this portrayal, Nephi does not premeditate the murder of Laban. He does not plan the killing when going back into the city at all.
Nephi goes back into the city by himself with no plan except being, ‘…led by the Spirit, not knowing beforehand the things which I should do.’ (1 Nephi 4:6). Nearby Laban’s house Nephi finds Laban drunk and presumably unconscious. With multiple and explicit instructions, Nephi takes the sword of Laban and cuts off the head of Laban.
Premeditated [Or Not] Importance
Nephi, writing this account much later in life, clearly wants the reader to understand he did not plan the killing, and he even hesitates against the Spirit of the Lord at first when told to slay Laban. Two times the Spirit directly tells Nephi to slay Laban and gives clear reasoning, “…the Lord hath delivered him into thy hands…” [see 1 Nephi 4:11&12]
Scholar and Biblical Law expert John Welch contends for examining Nephi’s killing of Laban in the context of Exodus chapter 21 [Read his complete and excellent article here]. See verses 12-14:
He that smiteth a man, so that he die, shall be surely put to death. And if a man lie not in wait, but God deliver him into his hand; then I will appoint thee a place whither he shall flee. But if a man come presumptuously upon his neighbour, to slay him with guile; thou shalt take him from mine altar, that he may die.
The scripture above lays out two important points under which killing needed to be examined during the time period of ancient Israel under the Mosaic Law.
Was the killing planned ahead?
Did God deliver a person to be killed?
Welch outlines how not planning the killing ahead of time changed the consequence. God’s intervention in the killing changed the guilt.
The final outcome to a 1. No and 2. Yes meant banishment from the area to preserve the life of the person who killed to prevent retribution. In Exodus when God commanded a killing, he also provided a place to flee for the one who killed.
For those familiar with Nephi’s account, the scriptures in Exodus ring a clear answer to both questions. First, Nephi did not plan to kill Laban – quite the opposite. Second, the Lord delivered Laban to Nephi to be killed. The Spirit of the Lord repeatedly speaks to Nephi apparently appealing to Exodus on a unique situation from the Law. The exact issue presented before Nephi.
Nephi writes his account after already inheriting a Land of Promise from the Lord. Originally promised to his father for an inheritance, obeying his father Lehi’s command to obtain the plates ultimately took Nephi on multiple journeys of his own. Nephi does not shy away from sharing his story of killing Laban, but readers can appreciate how Nephi draws attention to Exodus 21 and how the Lord fulfills His promise to give Nephi a place where he can flee.
How would the Law of Moses judge Laban’s actions?
Bearing False Witness
The Old testament explicitly outlines how to handle someone who breaks the ninth commandment and bears a false witness. A false witness is one of the six things God hates (Proverbs 6:16-19) and the book goes on to declare a false witness will perish if unrepentant (Proverbs 21:28). David commanded the killing of an Amalekite who falsely portrays himself as having killed King Saul (see 2 Samuel 1 and compare with 1 Samuel 31).
For the unrepentant and guilty bearer of false witness, Deuteronomy chapter 19 explicitly explains the bearer of false witness should suffer equal punishment they tried to inflict upon the falsely accused. Laban bore false witness and abused his power to kill the innocent parties. By all scriptural accounts and longstanding Jewish tradition, had truth come out in a fair trial Laban would have in all likelihood been executed. 
No Fair Trial Offered
Of course, no fair trial could possibly avail Nephi and his brothers. Still, with heavenly direction, individuals in the Old Testament did take direct and swift action to kill without a trial. To preserve Israel and end a plague of judgement, the priest Phineas kills Zimri and Cozbi for their immoral sin against of the Law of Moses. (see Numbers 25)
Sacrifice to Preserve the Nation
Some scholars have compared Nephi’s killing of Laban with a Biblical practice from ancient Israel where a guilty individual suffers punishment to preserve a group.  Consider 2 Samuel 20 where King David seeks to kill a treasonous rebel. The rebel, Sheba, hides inside the city of Abel. When David’s commander requests Sheba’s release, the city beheads Sheba and David’s armies retreat fully satisfied.
The Spirit of the Lord commands Nephi to slay Laban and perfectly explains the concept killing a guilty party to preserve the group. The Spirit tells Nephi in 1 Nephi 4:13:
Behold the Lord slayeth the wicked to bring forth his righteous purposes. It is better that one man should perish than that a nation should dwindle and perish in unbelief.
Readers may still pause while reading 1st Nephi hearing a familiar ring in their minds that killing is wrong. THOU SHALT NOT KILL. Nephi paused, too. Resisted, even.
The same readers might also pause over the many Biblical references quoted above. Or possibly pause over the command of slaughter against the Canaanites in Deuteronomy 7:1-2. Multiple other examples from the Bible could be provided. Apologist William Lane Craig responds well to the question of human morality contrasted with a moral God. [See an excellent response by William Lane Craig on the topic here]. According to Craig, Genesis 15:13&16 outlines how God waits to free Israel from slavery for 400 years because of his mercy upon the inhabitants of Canaan .
The same faithful reasoning of morality holds equally true for Laban. The Lord is merciful to Laban with two attempts from the family of Lehi to obtain the plates. One substantial offer would have presumably compensated for the financial loss of the artifact. Laban not only refuses both offers but reacts in ways arguably worthy of death as interpreted in the Mosaic Law.
Yet, even in contemporary times the examples above from the ancient world don’t stray immeasurably far from society. Shake a soldier’s hand who served. The concept of preserving a nation through individual sacrifice impacts every nation on all sides. Not just Nephi for a nation to come. Not just Israel and a monarchy from the past.
Readers pausing in 1st Nephi, but sincere and professing Christians or Jews must examine the Old Testament and key principals contained. The Book of Mormon intertwines a specific, historical first hand account where the Old Testament law comes into full play. Nephi killing Laban only makes sense in context of who he was [Hebrew], where he lived [land of Jerusalem], and when he lived there [~600BCE] before the Babylonian conquest.
Ultimately, the final instruction for Nephi to slay Laban to preserve a future nation should hit home to every professing Christian who accepts the sacrifice of Jesus Christ. Ancient Israel delivered Samson for judgement to preserve the people. As a type and shadow, these Old Testament individuals shadow the great individual sacrifice to come bearing the guilt of all to preserve a righteous group . The story of Nephi killing Laban rings true historically within the culture of his day and stands worthy of further research and additional studies for religious value for our day and time. Nephi kills Laban, but does not murder him.
John W. Welch, "Legal Perspectives on the Slaying of Laban," Journal of Book of Mormon Studies 1/1 (1992): 119–141.
The Commandments Vol. 1 p. 193 as quoted and discussed in Teaching Mitzvot: Concepts, Values, and Activities by Bruce Kadden, 2003, p. 107.
See John W. Welch and Heidi Harkness Parker, “Better That One Man Perish,” in Pressing Forward with the Book of Mormon: The FARMS Updates of the 1990s, ed. John W. Welch and Melvin J. Thorne (Provo, Utah: FARMS, 1999), 17–18.
William Lane Craig. (2020) '#16 Slaughter of the Canaanites' ReasonableFaith.org August 06, 2007. Available at: https://www.reasonablefaith.org/writings/question-answer/slaughter-of-the-canaanites/ .(Accessed: 1/24/2020)
David Crosley. 'Samson a Type of Christ'. Being a Sermon, Preached in London, July 28, 1691, at a Morning-Lecture, Upon Judges XIV. 5. Third Edition.