Translation analysis: The most important point of this verse is the change from the Isaiah text to the 2 Nephi text. In Isaiah we have:
Isaiah 9:3: Thou hast multiplied the nation, and not increased the joy: they joy before thee according to the joy in harvest, and as men rejoice when they divide the spoil.
In Isaiah, the phrase is “not increased the joy” where the Book of Mormon removes the “not.” Thus the phrasing becomes precisely the opposite in the Book of Mormon text. The textual evidence for this passage varies precisely at this point, with some texts having l’ (“not”) and others lw (“for him”). Tvedtnes notes that both words are pronounced the same, and therefore the divergent strains of the text can be explained on the basis of a scribal change in the similar sound (Tvedtnes, John A. “Isaiah Textual Variants in the Book of Mormon” FARMS 1981, p. 46).
Both Gileadi and the NIV follow the Book of Mormon’s removal of the “not,” leaving the message a positive one. As with the contextual reading of the first verse that sees the contrast between darkness/light, former/latter as the governing structure, so in this verse, the contrasting structures would appear to require this to be a future state where the increased joy is being contrasted with the previous darkness and sorrow.
A second change in the Book of Mormon text is the removal of the final phrase of the Isaiah text:
Isaiah 9:4 For thou hast broken the yoke of his burden, and the staff of his shoulder, the rod of his oppressor, as in the day of Midian.
There is no specific reason for the deletion of this text. Tvetnes suggests that it was either a textual variation on the Brass Plates, or an “accidental deletion by Joseph Smith, his scribe, or the printer. It is there in the [Masoretic Text].” (Tvedtnes, 1981, p. 46).
The reference is to the delivery of the Midianites into the hands of Gideon (see Judges 7:7-25). Thus the text is supportive of the theme of the eventual delivery of the enemies into the hands of the righteous. While it might be suggested that the Nephites would not understand the reference, there is no other indication of a similar deletion by Nephi. It would appear that either the textual variation or accidental deletion would be the best explanation, with a higher probability to the accidental deletion, as the brass plate text appears to follow the received text rather closely in most cases.
Literary analysis: Isaiah appears to be echoing the words of the 23rd Psalm in this prophecy. The Psalm reads:
Psalm 23:4 Yea, though I walk through the valley of the shadow of death, I will fear no evil: for thou art with me; thy rod and thy staff they comfort me.
The “land of the shadow of death” in Isaiah’s verse 2 echoes the “valley of the shadow of death” from psalms. In verse 4 we have the image of the rod and the staff. Of course the rod and staff are symbolic of the Lord in Psalm and are representative of the Assyrians (and any other worldly government) in Isaiah, but the closeness of the images opens the probability that Isaiah intended at least an oblique reference to the Psalm.
Scriptural analysis: The hopeful note begun in verse 2 is amplified in verses 3 an 4. Once again, there are at least two ways to read the prophecy - one as an imminent act, and one which describes a prophetic future not tied to the timelines of men.
The specifics of verse 4 speak of throwing off the yoke of an oppressor. This is in the near future for Judah, during the reign of Hezekiah, son of Ahaz. The questionable timeframe comes from verse 3 that correlates the deliverance to a harvest. While the image loosely fits the political redemption, Isaiah’s theme of the harvest victory appears more eschatological than imminent. The harvest comes in the far future with the final victory in the whole war, not the temporary victory of a single battle. Thus we continue the dual reading of the verses which have a simultaneous applicability to the near and long distant future.
Symbolic analysis: The rod and staff are symbols of both political and military power. In Psalms it is the Lord who provides the government and the protection. Each of these symbols appears to relate to a specific physical symbol, the rod as a shorter stick used in defense, and the staff as not only a larger defensive weapon, but as a representation of the authority of the bearer.
Later in Isaiah we find:
Isaiah 10:15 Shall the axe boast itself against him that heweth therewith? or shall the saw magnify itself against him that shaketh it? as if the rod should shake itself against them that lift it up, or as if the staff should lift up itself, as if it were no wood.
The shaking of the rod suggests the rod used in defense. The raising of the staff suggests Moses raising his staff to sustain his troops in battle. The staff also serves as an instrument of authority for an angel before Gideon:
Judges 6:21 Then the angel of the LORD put forth the end of the staff that was in his hand, and touched the flesh and the unleavened cakes; and there rose up fire out of the rock, and consumed the flesh and the unleavened cakes. Then the angel of the LORD departed out of his sight.