This people have I formed for myself; they shall shew forth my praise.
21. This people have I created for myself. The Prophet means that the Lord will necessarily do what he formerly said, because it concerns his glory to preserve the people whom he has chosen for himself; and therefore these words are intended for the consolation of the people. “Do you think that I will suffer my glory to fall to the ground?
Israel's faith had sunk so low that God must repeat His promise again and again. He takes the title Redeemer as His office and business; He will be all they need. Babylon must fall so His people may go free, and their cruel masters will perish even in their ships.
AI summary
Commenting on Isaiah 43:14-21
But thou hast not called upon me, O Jacob,.... The Jews, though they were the posterity of Jacob, a praying person, yet did not tread in his steps, but were more like the Heathens that called not on the name of the Lord; though there is no necessity of restraining this to prayer, it may regard the whole worship of God, which is sometimes included...