He upon whom the six-winged seraphim cannot look, being unable to gaze intently not only at His nature but even at the radiance of His glory, and therefore covering their eyes with their wings (Isaiah 6:2), having become flesh, appears to our senses and can be seen by bodily eyes.
He who defines all things and is limited by none is contained in a small, makeshift manger. He who holds the universe and grasps it in the hollow of His hand is wrapped in narrow swaddling bands and fastened into ordinary clothes.
He who possesses the riches of inexhaustible treasures submits Himself voluntarily to such great poverty that He does not even have a place at the inn; and so He enters into a cave at the time of His birth, who was brought forth by God timelessly and impassibly and without beginning.
[…] Anyone who has been vouchsafed understanding and grasped the honour which our nature received from God through being formed by His hands in His own image, will run towards Him, having come to a realization of His love for mankind, and will obey Him and learn His commandments. But how much more so if he comprehends, as far as is possible, this great mystery of our re-creation and restoration.
God formed human nature out of the earth with His own hand and breathed His own life into man (Genesis 2.7; 1 Thessalonians 5.23), whereas everything else He brought into being by His word alone. He then allowed man to be governed by his own thoughts and follow his own initiative, because he was a rational creature with a sovereign will.
Left alone, deceived by the evil one’s counsel and unable to withstand his assault, man did not keep to what was in accordance with his nature, but slid towards what was unnatural to it. So now God not only forms human nature anew by His own hand in a mysterious way, but also keeps it near Him.
Not only does He assume this nature and raise it up from the fall, but He inexpressibly clothes Himself in it and unites Himself inseparably with it and was born as both God and man: from a woman, in the first instance, that He might take upon Himself the same nature which He formed in our forefathers; and from a woman who was a virgin, in the second, so that He might make man new.
Gregory Palamas (1296-1359): Homily 58, on the Holy Nativity of the Lord. From Saint Gregory Palamas: The Homilies (Mount Thabor Publishing, 2009) @ Greek Orthodox Cathedral of the Ascension, Oakland, California.