2 Nephi 18

2 Nephi 18;  Isaiah 8

2 Nephi 18: 1-13

riches and spoil taken away......................................predicted fall of the nation of Assyria
refuse waters of Shiloh..................................................probably baptism or ritual washing?
waters of the river....................................................imminent invasion and enslavement
fill the land..........................................................the invasion will penetrate into Judah
broken...................................................................those who join with Damascus cursed
come to naught......................................................divinely controlled events
Him, the dread..........................................................only God is worshiped, not other countries

Isaiah prophesies the confederacy of Israel with Assyria, and he foretells its demise.  The Lord protests his people, and the people who follow the Lord under protection

2 Nephi 18: 14-22

stone of stumbling...............................................you cannot proceed without confronting
many snared.......................................................those who are not following the faith, enslaved
bind testimony.................................................teach the people, warn, and commit them to make a choice
signs and wonders..............................................the Lord protects his people, Miracles follow
peep............................................................those who follow animistic religion are doomed
no light.........................................................only the promises of God prevail.  Other sources fail
see trouble and darkness................................those who forsake God receive no help in troubles

The problem for the people is that they have abandoned God, and will not, therefore, receive help in their hour of need.

Isaiah is told to teach the people repentance, even if the people reject the message.  The fact that they receive the knowledge of the impending trials will hold them responsible for the consequences.