1. The Lord is my strength (1-3)

This is a conclusion of Ch1-12. God was angry against Israel for their sins. God judged Israel severely but it was to heal her and to give her salvation. Now the day came for God to comfort Israel. Now they can praise, "Surely, the Lord, the Lord is my strength. I will trust and not be afraid. He has become my salvation!" There is no salvation in this world except Jesus who is the well of salvation. When we are weary and thirsty, we should go to Jesus. He will forgive all our sins and fill us with joy from his spring of living water.

2. Make it known among the nations (4-6)

God saved Israel so that they may proclaim the name of God to all nations. God sent Immanuel, the shoot of Jesse. He died for our sins. But God raised him to give us eternal life. He also made us as his remnants. Therefore I will not only sing to the Lord but also make him known to the entire world. (Mat 28:20)