As with most commentators in the Christian tradition, Martin Luther (1483-1546) finds the Trinity revealed in Genesis 1:2, recognizing that the presence of the Holy Spirit must be intended, as there could not yet be wind, for heaven and earth had not yet been distinguished in the order of creation. To illustrate the role of the Spirit in creation, he pictures it as a hen, brooding over its eggs and thus nursing them to life.
Now the earth was formless and empty, darkness was over the surface of the deep, and the Spirit of God was hovering over the waters.
Commentary on Genesis 1:2
Some explain that “the Spirit of the Lord” simply means “wind.” . . . But it is more to my liking that we understand Spirit to mean the Holy Spirit. Wind is a creature which at that time did not yet exist, since so far those masses of heaven and earth lay mixed together. Indeed, it is the great consensus of the church that the mystery of the Trinity is set forth here. The Father creates heaven and earth out of nothing through the Son, whom Moses calls the Word. Over these the Holy Spirit broods. As a hen broods her eggs, keeping them warm in order to hatch her chicks, and, as it were, to bring them to life through heat, so Scripture says that the Holy Spirit brooded, as it were, on the waters to bring to life those substances which were to be quickened and adorned. For it is the office of the Holy Spirit to make alive.
Genesis 1-11, ed. John L. Thompson, Reformation Commentary on Scripture, OT vol. 1, 19.