From the introduction to Lewis’s Reflections on the Psalms:

It seems to me appropriate, almost inevitable, that when that great Imagination which in the beginning, for Its own delight and for the delight of men and angels and (in their proper mode) of beasts, had invented and formed the whole world of Nature, submitted to express Itself in human speech, that speak should sometimes be poetry.  For poetry too is a little incarnation, giving body to what had been before invisible and inaudible.