This part of Isaiah speaks of the ministry of the Messiah. The shedding of His blood will serve to heal the sins of Israel and the nations.

Because of Zion's sins, God will make / has made them drink from the cup of staggering. Once that cup has been drained, His wrath will be complete and Zion will be restored in glory. The exile of Judah was yet future to Isaiah's time. Their complete restoration is yet future to us.

The Messiah will bring the scattered exiles of Jacob back to the Land. Their numbers will be so great that the current boundaries of Israel will not suffice. In this, Isaiah prefigures the greater Exodus written of in Jeremiah 16.

Isaiah's prophecy is over a century before the Babylonian exile; yet here he predicts exile, return and the ultimate destruction of the ancient system of rebellion and false worship represented by Babylon. In this he reaches all the way to the end times.

Isaiah, writing almost a century and a half before the event, predicted the rise and career of Cyrus the Persian. He asserted that all of Cyrus' military success was attributable to the hand of God and that Cyrus would send Judah back to their land after the Babylonian exile. This prophecy so impressed the king that he not only released the Jews but financed the rebuilding of the Temple.

Men are continually tempted to make and worship idols. The prophet mocks that as foolishness and holds Israel up as a witness to the power of God in contradistinction to the futility of idolatry.

Beginning with 'Sing to the Lord a new song,' this section goes on to explain that the servant of the Lord (Israel in this case) has been scattered because of spiritual blindness. It goes on to promise that God will redeem Israel and cure that blindness.

When Isaiah speaks of the servant of the Lord, sometimes he means Israel, sometimes the Messiah. Discerning which can sometimes be difficult. In this passage, it seems to be the Messiah.

Change of subject from the Assyrian invasion to a long prophetic section of the book. Here the prophet looks forward to the exile of Judah, the coming of the Messiah and the eventual return of the nation. The futility of idols and God's love for His people will be a recurring theme in the following chapters.

Hezekiah, faced with an illness unto death during the Assyrian invasion, prayed for deliverance. God answered his prayer, granting the king an extra 15 years of life. As a sign of His favor, God backed up the shadow on the sundial by ten steps. The effects of this event are recorded as well in secular history.