The prophet offers up a song of praise to God, sung in response to the news of Yahweh’s future restoration of the people of Judah, which God has promised to send His servant, an apparent reference to the coming Messiah, who will rescue, restore and redeem the people of God.
Six of the psalms talk about a “new song” (Psalms 33:3; 40:3; 96:1; 98:1; 144:9; 149:1). He is a God of variety and creativity, so it is fitting that the prophecies of Isaiah and Revelation also talk about new songs.
Praising God helps us to focus on reality—what’s truly permanent in our chaotic and transitory lives. Focusing only on the physical things that can be shaken leaves us unstable. But focusing on spiritual things gives us a firm foundation that cannot be shaken (Heb. 12:25-28).
When we look back to all that God has done in our lives and how he’s delivered us from all our fears, every time – despite uncertainties or odds against us, we can only be grateful and sing praises to our God. "He put a new song in my mouth, a hymn of praise to our God" (Psa. 40:3).