How Old Was Nephi When He Left Jerusalem?

Following the tradition of ancient Israel, Lehi would have been married before he turned thirty years of age. Considering him to be about 25, and having children immediately, Lehi would have been around 27 when his oldest was born. His wife, Sariah, would customarily be about ten years younger than he. According to Nephi’s record, we know of four sons born to Lehi while living at Jerusalem (1 Nephi 2:5). We also know that Jacob and Joseph were born in the wilderness (1 Nephi 18:7), and when we find them in the promised land later, Nephi casually mentions having at least two sisters (2 Nephi 5:6).

In addition, Erastus Snow has said that Ishmael's sons married into Lehi's family, and since Ishmael's two sons were already married with families (1 Nephi 7:6) before leaving Jerusalem to join the Lehi Colony, it can be assumed that these two sons had married two older daughters of Lehi not specifically mentioned in scripture. Thus, Lehi may have had at least six children at the time he left Jerusalem. Assuming he was 26 or 27 when the oldest was born, he would have been at least 36 when Nephi was born.
If Laman was born first, this could put as much as ten years in age difference between himself and Nephi. This would explain some of Laman's later antagonism toward Nephi, lack of acceptance in a younger brother's abilities, and his irritation about a younger brother trying to usurp his right of leadership and inheritance.

George Q. Cannon concluded that “Nephi was probably not more than fifteen years old” when he left Jerusalem. Other writers on this subject have suggested that Nephi was sixteen when leaving Jerusalem, seventeen when the Lord visited him, eighteen when he beheaded Laban and seized Zoram, and perhaps nineteen years old when he married.

However, these estimates are usually made based upon Nephi's own statement describing himself as “being exceeding young, nevertheless, large in stature” (1 Nephi 2:16). Yet, soon after leaving Jerusalem, we find Nephi taking command and leading his brothers back to Jerusalem, seizing and holding Zoram, a grown man (1 Nephi 4:31), and cutting off the head of Laban with a man's sword (1 Nephi 4:18). Thereafter, he had the timber of voice, and stature of character, to pose as Laban in the man’s armor, and fool Laban’s trusted servant, Zoram (1 Nephi 4:21),
And even his brothers when they first saw him (1 Nephi 4:28). Shortly there after, he had a vision of the Savior (1 Nephi 11), and not too long after that, he married one of the daughters of Ishmael (1 Nephi 16:7). These latter events do not fit into a youth of “exceeding young” age, despite his being large in stature. In fact, the word exceeding, as used elsewhere, would mean considerably, unusually, greatly, etc. When used against age, this would suggest that he was very young, maybe even ten or twelve as such a term would warrant.

However, when compared with the Jewish thinking of his day, Nephi's exceeding young age takes on another meaning. By custom, Jews were not considered old enough to preach until they were 30, when they came of age in wisdom and understanding. Jews had to be 30 and married to belong to the Sanhedrin. Customarily, men married in their mid to late twenties, typically taking a wife at least ten years their junior (Joseph was an older man when he married the young Mary; by older, he may have been as much as 30 years old and Mary as young as 15). In a land and among a people who considered men under the age of 30 to be immature and lacking in wisdom and learning, it would be understandable for a young man, even around 20, to consider himself “exceeding young” when compared to men of age and wisdom.

In addition, Nephi makes this comment thirty years after leaving Jerusalem when he is much older, perhaps about 50 to 60, and looking back over the travails of his life, considered himself “exceeding young” at the time he left Jerusalem in experience and understanding of all that he must encounter. It is not uncommon for men of achievement to look back on their younger years and consider how young and inexperienced they were.

It seems likely that Nephi was at least 20 to maybe 25 when he left Jerusalem. This would both allow him to overpower a grown man, have the self-confidence required to obey the Lord in such matters as killing a man, the self-assurance to impersonate Laban, the intellect to outwit Zoram, the character to take charge and lead his older brothers, the wisdom to convince Ishmael to join the Lehi Colony, and the maturity to marry—all within a time frame of about two years of his leaving Jerusalem. While Joseph Smith was a boy of 14 when he received his first vision, the Lord waited four years for the boy to mature enough to receive the gold plates, during which time he had constant training from the angel Moroni.

If Nephi was about 20 when leaving Jerusalem, he would have been about 28 when he forged the ore to make the tools to build a ship, about 30 when he set foot in the promised land, around 40 when he forged a new nation, ruled as king, and led the defense of his people after the schism with his brethren. Continuing on, this would have made him about 50 when he sat down to abridge the Large Plates in the promised land, and seventy-five when he turned over the responsibilities of being prophet to his younger brother, Jacob (Jacob 1:1). If he was 25 when leaving Jerusalem, he would have been about 80 when he relinquished those responsibilities to his younger brother—who would have been some 30 years his junior.

To be about 15 or younger as some claim, would have made Nephi far too young to marry in the custom of the Jews of the day. He would also have been extremely young to follow the foregoing time line with any success.