John Calvin Commentary Isaiah 42:7

"to open the blind eyes, to bring out the prisoners from the dungeon, and them that sit in darkness out of the prison-house." — Isaiah 42:7 (ASV)

That thou mayest open the eyes of the blind. Here he explains more fully for what purpose Christ will be sent by the Father, so that we may see more clearly what advantage He provides us, and how much we need His assistance. He reminds all people of their blindness, so that they may acknowledge it, if they wish to be illuminated by Christ. In short, through these metaphors he declares the condition of humanity until Christ shines upon them as their Redeemer; that is, that they are most wretched, empty, and lacking all blessings, and surrounded and overwhelmed by countless distresses, until they are delivered by Christ.

Now, although the Prophet addresses Christ Himself, he also has believers in view, so that they may know that they ought to trust in Him, and may not doubt that a remedy will be provided for all their distresses, if they implore His aid. God does not here command Christ what He should do, as if He needed to be taught or to receive commands; but He addresses Him for our sake, so that we may know why the Father sent Him; as He also says (Psalms 2:7–8), I will make known the decree; ask of me, I will give thee the Gentiles. For in that passage the rank and authority of Christ are declared, so that we may know that the Father has bestowed on Him the highest authority, in order that we may more securely place all our hope and confidence in Him.