I am Jehovah. He confirms the preceding statement, and the repetition is not superfluous; for it was proper that it should be often repeated to Cyrus, that there is one God, by whose hands all rulers and nations are governed, that he might be drawn aside from all delusions and be converted to the God of Israel. Besides, it is clearly stated that we ought not to try to find divinity in any other; as if he had said, "Beware of ascribing this victory to idols, or forming any confused idea of a god such as men imagine; know that the God of Israel is the only author of this victory." Although Cyrus did not profit by this admonition to such an extent as to leave his idols and devote himself to the true God, yet it made so deep an impression on his heart that he acknowledged Jehovah to be God and to possess the highest authority. At the same time, it was proper that they who were members of the Church should embrace this doctrine, that they might boldly despise all pretended gods. I have girded thee. That girding corresponds to the nakedness which he formerly mentioned, (verse 1,) when he said that he "opened" or "ungirded the loins of kings;" for he is said to "gird" those whom he supplies with strength and courage and renders victorious. Hence it ought to be inferred, that men have no courage but when the Lord imparts to them his power and strength, that neither weapons nor any military force can do anything unless he assist, and, in a word, that he presides over all wars, and gives victory to whomsoever he pleases, that none may think that it happens by chance. He again repeats, Though thou hast not known me, in order to make it still more certain that these things are granted to Cyrus for the sake of the Church, in order that he may give evidence that he remembers it with gratitude, and may shew kindness to the people of God in return for such a distinguished favor.

I am the Lord - (see the notes at Isaiah 42:8; Isaiah 43:2; Isaiah 44:8; Isaiah 45:14, Isaiah 45:18, Isaiah 45:22).
I girded thee - (see the note at Isaiah 45:1). The sense is, I girded thee with the girdle - the military belt; I prepared thee, and strengthened thee for war and conquest. Even people who are strangers to the true God are sustained by him, and are unable to accomplish anything without his providential aid.

I [am] the LORD, and [there is] none else, [there is] no God besides me: I (g) girded thee, though thou hast not known me:
(g) I have given you strength, power and authority.

I am the Lord, and there is none else,.... Whom thou, O Cyrus, for the words are directed to him, ought to own, serve, and worship:
there is no God besides me; in heaven or earth, in any of the countries conquered by thee, and thou rulest over; for though there were gods and lords many, so called, these were only nominal fictitious deities; not gods by nature, as he was; of which the following, as well as what is before said, is a proof:
I girded thee, though thou hast not known me; the Lord girded him with a royal girdle, a symbol of kingly power; he made him king over many nations; he girded him with strength, courage, and valour for war; and made him so expeditious, successful, and victorious, as he was, though a Heathen prince, and ignorant of him, in order to answer some valuable ends of his own glory, and the good of his people, and particularly for what follows.

There is no God beside Jehovah. There is nothing done without him. He makes peace, put here for all good; and creates evil, not the evil of sin, but the evil of punishment. He is the Author of all that is true, holy, good, or happy; and evil, error, and misery, came into the world by his permission, through the wilful apostacy of his creatures, but are restrained and overruled to his righteous purpose. This doctrine is applied, for the comfort of those that earnestly longed, yet quietly waited, for the redemption of Israel. The redemption of sinners by the Son of God, and the pouring out the Spirit, to give success to the gospel, are chiefly here intended. We must not expect salvation without righteousness; together the Lord hath created them. Let not oppressors oppose God's designs for his people. Let not the poor oppressed murmur, as if God dealt unkindly with them. Men are but earthen pots; they are broken potsherds, and are very much made so by mutual contentions. To contend with Him is as senseless as for clay to find fault with the potter. Let us turn God's promises into prayers, beseeching him that salvation may abound among us, and let us rest assured that the Judge of all the earth will do right.

(Isaiah 42:8; Isaiah 43:3, Isaiah 43:11; Isaiah 44:8; Isaiah 46:9).
girded thee--whereas "I will loose (the girdle off) the loins of kings" (Isaiah 45:1), strengthening thee, but enfeebling them before thee.
though . . . not known me-- (Isaiah 45:4). God knows His elect before they are made to know Him (Galatians 4:9; John 15:16).

I girded - I made thee strong and active, and disposed thee for these great and warlike enterprizes.