There was a lot of pressure for Nephi to get ahead.
There are a great number of people both in and out of the Church who have a hard time defending or justifying Nephi in the Book of Mormon decapitating Laban. (1 Nephi 4:18)
The essence of the story involves Lehi receiving a dream wherein he was commanded by the Lord to acquire the scriptures and genealogy from a relative of Lehi from the Tribe of Joseph whose name was Laban. (1 Nephi 5:16). According to Jewish patriarchal tradition the clan leader was to keep the family records and histories.[1] Lehi requested that his sons Laman, Lemuel and Sam with Nephi confront Laban and ask for the records from Laban who was the keeper of the clan records.[2] Nephi did not murmur at his father’s request to go to Jerusalem and acquire the records which were written on plates of brass. Lots were cast and the lot fell to Laman. Laban rejected Laman’s request for the records and accused Laman of being a robber. Laman fled for his life. Through Nephi’s perseverance the brother’s agreed to go down to the land of their father’s inheritance and take gold, silver and precious things to Laban in exchange for the records. Once again Laban rejected the offer but kept their “exceeding great” gold, silver and precious things. The brothers fled once again. On the third attempt it was only Nephi who returned to Jerusalem, “not knowing beforehand the things which” he should do. It was night when Nephi encountered a drunken Laban lying on the street. He was impressed by the Spirit that he should slay Laban for the Lord had delivered him into Nephi’s hands.
The King James Version of the Bible uses the words, “Thou shalt not kill.” However the Hebrew word is thou shalt not murder. Murder is the unlawful taking of human life. Justifiable homicide in ancient Israel involved killing someone under certain conditions. Killing was legal if someone was in possession of your stolen goods as was Laban and it was during the night. (Exodus 22:2-3). Laban was probably drunk after celebrating his ill-gotten gains. If someone is killed because the Lord delivered him into the killer’s hand he is justified and the Lord will appoint a place for the killer to flee. (Exodus 21:12-13, 1 Nephi 4:11). The Lord appointed an area by the Red Sea as a place for Nephi to flee. Nephi and his brethren returned to their father’s tent with the plates of brass.
Samuel Decapitates Agag and More
Samuel was a Prophet and Seer and was commanded to send King Saul and the armies of Israel to wipe out the Amalekites. “Now go and smite Amalek, and utterly destroy all that they have, and spare them not; but slay both man and woman, infant and suckling, ox and sheep, camel and ass. (1 Sam 15:3). It was the Amalekites that attacked the Israelites from behind when they were leaving Egypt and killed the most feeble and helpless of Israel. (Deut. 25:17-19). In Exodus 17:14, God swore to Moses this: “I will utterly blot out the memory of Amalek from under heaven.” In Numbers 24:20 Balaam prophesied the destruction of the nation of Amulek. However, Saul kept the Amalekite King Agag alive as well as the best of the sheep, oxen and lambs. The result of Saul’s disobedience was that he lost his kingship. Samuel took Agag and hewed him in pieces before the Lord in Gilgal. Apparently there are times when even Prophets like Nephi and Samuel are commanded to commit justifiable homicide.
[1] The family was aptly termed bet av (“house of a father”; e.g., Gen. 24:38; 46:31). To found a family was “to build a house” (Deut. 25:10). The bayit (“house”) was a subdivision of the mishpaḥah (“clan, family [in the larger sense],” Josh. 7:14). The criterion for membership in a family was blood relationship, legal ties (e.g., marriage), or geographical proximity…The father was the head of the family unit and owner of its property (Num. 26:54–55). He was the chief authority and, as such, is portrayed as commanding (Gen. 50:16; Jer. 35:6–10; Prov. 6:20) and rebuking (Gen. 37:10; Num. 12:14). https://www.jewishvirtuallibrary.org/family
[2] It is my studied opinion that Lehi may have been entitled to the records if he were the eldest male member of his “Clan.” Laban and his fathers kept the records but at the death of Laban’s father the records physically were kept in the care of Laban. However, Lehi may have been entitled to the records. It makes no sense that someone would request the family records unless he was entitled to them. This speculation is consistent with Jewish tradition.