"'This day they will halt at Nob; they will shake their fist at the mount of the Daughter of Zion, at the hill of Jerusalem.'" NIV translation
Isaiah assures the people that the Assyrians will not take Jerusalem and in fact their march was stopped. This is similar to what is coming in the future as described by John in Revelation 19 & 20. Today, there is much debate about a Mideast peace plan and the ownership of the city of Jerusalem. The fact of the matter is that God has chosen Jerusalem as His city and it cannot be changed.
"See, the Lord, the Lord Almighty, will lop off the boughs with great power. The lofty trees will be felled, the tall ones will be brought low. He will cut down the forest thickets with an ax; Lebanon will fall before the Mighty One." NIV translation
At this point in time, Lebanon was known for its great forests of cedar trees.
Isaiah tells them that judgment is coming and that even the great trees will be cut down.