Why was the Sword of Laban Found with the Plates in Cumorah?

My mission president asked this question to me 14 years ago and I thought I would include a letter he wrote me as I was assigned to serve as a trainer of a new missionary as an answer to that question:

Dear Elder,

I am writing to formally lend my support and congratulations in your calling as a trainer in this mission. As you realize by now due to the many discussions we have had, being called as a trainer is perhaps the single most important calling you can receive while serving in this mission.

Because (this mission) is a newly formed mission in the world it is an opportunity to establish the foundation and train the future leaders of the mission in a way that will be an example. As we read in 1 Nephi 4:9

"And I beheld his sword, and I drew it forth from the sheath thereof; and the hilt thereof was of pure gold, and the workmanship thereof was exceedingly fine, and I saw the blade thereof was of the most precious steal."

And so are you Elder as we pull you from the troops in the mission field; with a spirit of pure gold, representing a workmanship that is exceedingly fine, with an understanding of the gospel, and a testimony of most precious spirit. If we recognize the tremendous workmanship and value of this sword so we recognize also the tremendous value and workmanship of you and the importance of what will come of your example. As we read in 2 Nephi 5:14:

And I, Nephi, did take the sword of Laban, and after the manner of it did make many swords..."

I learned that now we might be able to make many missionaries after your example and your commitment. That this mission will grow stronger because of that. That you will bring a blessing and a strength to the future generation of this mission by your actions and your commitment to be dedicated in training and directing this new missionary. That he will have a vision with an insatiable desire to climb to the highest peaks and perform that work that the Lord has prepared and must be done...

We pray that you will be as the sword of Laban and always be an example of highest quality, obedience and workmanship.

The fact that this sword was carried by prophets and leaders of the Nephite nation is evidenced by Moroni including it along with the plates, the Urim and Thummim and Liahona. It was not only a token of Nephi's being led to find the record of his ancestors but became the standard in workmanship for all swords going forward.

Of course all of these items are a type of Christ in their own regard.

see also "The Sword of Laban as a Symbol of Divine Authority and Kingship" by Brett L. Holbrok - Journal of Book of Mormon Studies: Volume - 2, Issue - 1
Provo, Utah: Maxwell Institute, 1993