DO YOU WANT TO SEE the humility of God? Look in the manger and see him lying there. Surely this is our God. Seeing an infant, I wonder how this could be the one who says, "Do not I fill heaven and earth?" I see a baby wrapped in swaddling clothes. Is this the one who is clothed in the beautiful glory of unapproachable light?

Listen! He is crying. Is this the one who thunders in the heaven making the angels lower their wings? Yes, but he has emptied himself in order to fill us.

Guerric of Igny, Liturgical Sermons link