Receive, Lord, our gifts,That's my translation. Maybe someone can post how the English really goes (I don't have an English missal here) and we can see how close I got.
which exercise a glorious exchange,
that, offering what you have given, we may win you yourself.
That 'glorious exchange' is the joy of Christmas. We who have so little to give receive a gift greater than we can contain or comprehend: God himself. In the mystery of the Incarnation, God abandons his divinity into our humanity, lifting it into the mysterious inner life of the Blessed Trinity himself. This is the gift of which St. John speaks in the Gospel of Christmas Day: "But to all who received him, who believed in his name, he gave the power to become children of God; who were born not of blood nor of the will of the flesh nor of the will of man, but of God." (John 1:12-13) Our rebirth in God becomes available through the birth of the Word of God as one of us.
When we realize the depth and greatness of the gift we have received in Jesus Christ, no response makes sense but to give ourselves totally to him. Our giving of ourselves to God remains a gift ever meager and poor; God's gift of himself to us remains ever greater than we can think or imagine. As St. Francis puts it in the Letter to the Entire Order, "Hold back nothing of yourselves for yourselves, that He Who gives Himself totally to you may receive you totally."