From the book Festal Orations of St Gregory Nazianzus
Oration 45 'On Holy Pascha'
O the new mixture! O the paradoxical blending! He who Is comes into being, and the uncreated is created, and the uncontained is contained, through the intervention of the rational soul, which mediates between the divinity and the coarseness of flesh. The One who makes rich becomes poor; he is made poor in my flesh, that I might be enriched through His divinity. The Full One empties himself; for he empties himself of his glory for a short time, that I may participate in His fullness. What is the wealth of His goodness? What is this mystery concerning me? I participated in the divine image, and I did not keep it; He participates in my flesh both to save the image and to make the flesh immortal.