What does Isaiah 9:8 mean?

In his book, Isaiah often alternates between prophecies about great blessings set in Israel's distant future and great judgment in Judah's immediate future. He has just concluded describing the coming of the King Messiah, who will restore to Israel light, joy, and security. This Messiah will rule forever from the throne of David (Isaiah 9:6–7).

Now he returns to describing the events of his own day, starting with destruction of the nation now called Israel. This nation included the ten northern tribes. This is no mere prediction about bad times to come. Isaiah speaks on behalf of the Lord. It is the Lord who has sent a word against Israel. The nation of Israel is also referred to as Jacob.

Isaiah writes that the Lord's word will "fall on Israel." What the Lord declares always happens, unless He specifically says otherwise (Job 42:2; Psalm 33:10; Isaiah 14:27). From Genesis 1, the Lord speaks words into reality, whether that word creates something new or brings destruction to what exists. This "word" Isaiah is referring to goes out against Israel for the faithlessness of the people and their unbelief in the Lord.