If you want to get past the tinsel and ivy and the crush of shopping to recover the Christian meaning of the Birthday we approach, stop a moment and read Hebrews 10.
Most people, when they think of the relationship between the Old Testament and the New, account for that connection by referring vaguely to “promise and fulfillment”—as if it were simply a matter of prediction and occurrence. The reality is far more complex and interesting than that. The way the author of the letter to the Hebrews uses Psalm 40 to speak of the Incarnation is a stunning demonstration of how a Christian scribe brings from the storeroom of the Hebrew Scriptures “both the new and the old” (Mt 13:52).
The “something old” (and of continuing value) in Psalm 40 is its power as a prayer of thanksgiving for divine rescue and its claim that a heart obedient to God is a greater form of worship than temple sacrifices. The “something new” that the author of Hebrews finds there is how the psalm's words may be applied to the meaning of the life and death of Jesus.
A literal rendering of the Hebrew of Psalm 40:7 would be, “but ears you have dug for me.” That is such a blunt image that most translations paraphrase, to clarify the apparent intent of the image, as in “but you have given me an open ear” (NRSV) or “but ears open to obedience you gave me” (NAB). The author of Hebrews uses the quite different Greek version, which reads “but a body you have prepared for me.” Now, Psalm 40 in any version works wonderfully as an interpretation of Jesus' person and mission; indeed, he taught that love of God and neighbor is worth more than all Temple sacrifices (Mk 12:33).
But that Greek version, in what was the Bible of the early Church for the first three centuries, was a perfect vehicle for capturing the mystery of the incarnation—“a body you have prepared for me.” For the human body in which the eternal Son becomes enfleshed is the means by which this representative of humanity can respond in perfect obedience to God. The atonement that temple sacrifices meant to accomplish finally reached fulfillment in the body of Jesus. In that body Jesus was able to live out a life and death that sealed the renewed covenant prophesied by Jeremiah 31.
Thus our author has found the perfect Christmas card in a Greek Psalm. Like the prologue of the Fourth Gospel and the “emptying-out” hymn of Philippians 2:5, the theologian of Hebrews cannot speak of the incarnation without moving to its climax in the paschal mystery. If that seems to collapse into a synthesis what the liturgical seasons are careful to sort out and separate, these texts remind us that the Liturgical Year is, after all, a way of moving through aspects of a single vision—how the Creator reveals and redeems in Christ Jesus.