According to Potter and Wellington, Nephi’s words of warning to his brothers are fascinating. He has spent the previous 25 verses comparing his brothers with the children of Israel led to the wilderness by Moses. Yet now he changes the analogy to comparing them to a reed that will wither. Laman and Lemuel hadn’t seen a reed for 8 years while crossing the desert. Why would Nephi suddenly choose a reed? The answer perhaps is part geographical. In Khor Rhori, from the spot of the cliff where they were standing, less than 100 yards below them the banks of the khor are lined with reeds. As Nephi spoke those words, in the lull between the booming of the waves, the sound of the wind rustling through the reed beds would have been all too obvious. [George Potter & Richard Wellington, Discovering The Lehi-Nephi Trail, Unpublished Manuscript (July 2000), p. 270]
Note* Another reason for Nephi’s use of the term “reed” in warning his brothers might be that the term is often mentioned in the scriptures as a symbolic scepter of rulership and power, the exact thing that Laman & Lemuel were battling Nephi over. Isaiah says the following: “Now, behold, thou trustest upon the staff of this bruised reed, upon Egypt, on which if a man lean, it will go into his hand, and pierce it: so [is] Pharaoh king of Egypt unto all that trust on him” (Isaiah 36:6; see also 2 Kings 18:21). It is interesting that the soldiers mockingly used a reed for Christ’s scepter: "And when they had platted a crown of thorns, they put [it] upon his head, and a reed in his right hand: and they bowed the knee before him, and mocked him, saying, Hail, King of the Jews! (Matthew 27:29) [Alan C. Miner, Personal Notes]