But should it be the Jew who gainsays these arguments, our discussion with him will no longer present equal difficulty, since the truth will be made manifest out of those doctrines on which he has been brought up. For that there is a Word of God, and a Spirit of God, powers essentially subsisting, both creative of whatever has come into being, and comprehensive of things that exist, is shown in the clearest light out of the Divinely-inspired Scriptures. It is enough if we call to mind one testimony, and leave the discovery of more to those who are inclined to take the trouble.
“By the Word of the Lord,” it is said, “the heavens were established, and all the power of them by the breath of His mouth.” What word and what breath? For the Word is not mere speech, nor that breath mere breathing. Would not the Deity be brought down to the level of the likeness of our human nature, were it held as a doctrine that the Maker of the universe used such word and such breath as this? What power arising from speech or breathing could there be of such a kind as would suffice for the establishment of the heavens and the powers that are therein?
For if the Word of God is like our speech, and His Breath is like our breath, then from these like things there must certainly come a likeness of power; and the Word of God has just so much force as our word, and no more. But the words that come from us and the breath that accompanies their utterance are ineffective and unsubstantial. Thus, they who would bring down the Deity to a similarity with the word as with us render also the Divine word and spirit altogether ineffective and unsubstantial. But if, as David says, “By the Word of the Lord were the heavens established, and their powers had their framing by His breath,” then has the mystery of the truth been confirmed, which instructs us to speak of a word as in essential being, and a breath as in personality.
Source: The Great Catechism (New Advent)