Isaiah 42:5

Here is I. The covenant God made with and the commission he gave to the Messiah, Isa 42:5-7, which are an exposition of Isa 42:1, Behold my servant, whom I uphold. 1. The royal titles by which the great God here makes himself known, and distinguishes himself from all pretenders, speak very much his glory (Isa 42:5): Thus saith God the Lord. And who are thou, Lord? Why, he is the fountain of all being and therefore the fountain of all power. He is the fountain of being, 1. In the upper world; for he created the heavens and stretched them out (Isa 40:22), and keeps the vast expanse still upon the stretch. 2. In the lower world: for he spread forth the earth, and made it a capacious habitation, and that which comes out of it is produced by his power. 3. In the world of mankind: He gives breath to the people upon it, not only air to breathe in, but the breath of life itself and organs to breathe with; nay, he gives spirit, the powers and faculties of a rational soul, to those that walk therein.

— Matthew Henry's Concise Commentary (public domain)

Previously God had spoken of Messiah; now (Isa 42:5-7) He speaks to Him. To show to all that He is able to sustain the Messiah in His appointed work, and that all might accept Messiah as commissioned by such a mighty God, He commences by announcing Himself as the Almighty Creator and Preserver of all things. spread . . . earth-- (Psa 136:6).

— Jamieson-Fausset-Brown Commentary (public domain)