John Calvin on Isaiah 43:13

13. Even before the day was. He now speaks of the eternity of God; but we must attend to the Prophet’s design; for he who has a beginning and is not from himself, cannot rule by his dominion, or govern according to his pleasure, what he has not created. When, therefore, God declares that he is eternal, he reminds us that the world is his workmanship; for this order of nature did not spring up by chance, but proceeded from the wonderful purpose and. wisdom of God. (Genesis 1:1.) In this sense he afterwards adds, —

There is none to deliver out of my hand. Hence we shall clearly see that his supreme and infinite power is proved from his eternity; for if he were not eternal, he could neither exercise authority over all things, nor be the defender of his people, nor dispose of the creatures according to his pleasure; but since he is eternal, all things must be subject to his authority. To the same purpose is what he says, that no obstacle can prevent what he hath decreed to do, that the Jews may not be alarmed or dispirited by the forces or number of the enemies.