Theophylact of Ohrid — as excerpted in the Catena Aurea on John 6:55-59

“For we do not eat God simply, God being impalpable and incorporeal; nor again, the flesh of man simply, which would not profit us. But God having taken flesh into union with Himself, that flesh is quickening. Not that it has changed its own for the Divine nature; but, just as heated iron remains iron, with the action of the heat in it; so our Lord’s flesh is quickening, as being the flesh of the Word of God.”