Translation analysis: this verse is clearer in other translations. In the NEV we have:
The Lord has sent forth his word against Jacob and it will fall on Israel.
The NEV rendition more clearly underscores the shift in tenor from the Messianic to the proximate. Isaiah is returning from his eschatological future Messiah to a more immediate theme of the destruction of Israel. The word of God comes to all of the house o Judah, and the wrath of God for the violation of those covenants will first fall on Israel in the north.
Literary analysis: Isaiah begins here a series of four poetic stanzas. Each stanza is marked by the terminating phrase "For all this his anger is not turned away, but his hand is stretched out still." This same phrase will come at the end of verses 12, 17, 21, and again at 20:4 (following the division between Isaiah 9 and 10 in the OT division into chapters and verses). This becomes a marker of emphasis and parallels among the four stanzas.
The four stanzas alternate between two themes. The first stanza speaks of the people, then the next discusses the rulers. The third stanza concerns the people, and the last returns to the theme of the rulers. This poetic structure that clearly crosses the bounds of our current chapter 19 (Isaiah 9) into 20:4 (Isaiah 10:4) reinforces the wisdom of the 1830 Book of Mormon's more logical structuring of Isaiah that avoids this artificial break in an otherwise literary whole unit.
Scriptural analysis: The anger of the Lord is still upon an unrepentant Israel (and Judah). The stretching out of the hand can have two possible effects, for this is a common metaphor for the exercise of the Lord's power towards Israel or Judah. It is dual image in that the hand can be stretched forth as a protection and a blessing, or it may be clenched as a fist, or wielding a sword. It is probably that this verse is intentionally ambiguous as regards the intent of the Lord.
With this image, the Lord is shown ready to act. Whether to Israel's or Judah' benefit or harm will depend upon them. This first stanza shows the prophecy on a large scale, pertaining to leaders and lands.