When Benjamin is preparing Mosiah to be crowned king, he “gave him charge” over the plates of brass and the plates of Nephi, along with the sword of Laban and the ball/director (Liahona). Why were these items important to pass on and preserve? Many scholars have pointed out that they were both sacred objects representing God’s hand in leading the Nephites to the promised land and emblems of Nephite kingship which established the credibility and legitimacy of the Nephite rulers. They were parallel to the sacred objects stored in the ark of the covenant among the ancient Israelites.
Read athttps://knowhy.bookofmormoncentral.org/knowhy/why-did-the-nephites-preserve-some-items-as-national-treasures