Psalm 98 (numbered 97 in the Septuagint and Vulgate) is a jubilant enthronement hymn belonging to the post-exilic collection Psalms 93–99. Most scholars date its final form to the 5th–4th century BC, when the returning exiles experienced the restoration from Babylon as a second Exodus. With no trace of lament or petition, the psalm bursts into pure praise: God has revealed his salvation, his right hand and holy arm have triumphed, and now “all the ends of the earth have seen the salvation of our God.” Israel’s God is King over history and creation, and every nation is summoned to join the “new song.”

In the Roman Catholic Lectionary, this same joyful text (vv. 1–4 with v. 1a as refrain) serves as the Responsorial Psalm for two major solemnities that bookend the mystery of the Incarnation: Christmas Day (Mass During the Day) and the Immaculate Conception of the Blessed Virgin Mary (December 8).

On Christmas, the Church hears in the psalm the triumphant announcement of the Savior’s birth: the “wonders” God has worked reach their visible climax when the Word becomes flesh and “all the ends of the earth” behold his glory in the manger.

On the Immaculate Conception, however, the same verses are heard one step earlier in salvation history. The “wonder” God has worked is the singular grace granted to Mary: preserved from original sin from the first moment of her conception in view of Christ’s future merits. In her immaculate soul, the victory of the “right hand and holy arm” is already complete; she is the spotless dawn that precedes and prepares the rising Sun. Thus Mary herself becomes the first singer of the “new song,” the living proof that God’s merciful love and truth have triumphed even over humanity’s primordial wound.

Between these two feasts, Psalm 98 frames the entire drama of redemption: what begins silently and hiddenly in Mary’s Immaculate Conception is manifested to every nation in the crib at Bethlehem. The Church therefore repeats the same exultant refrain—“O sing a new song to the Lord, for he has worked wonders”—inviting us to marvel at both the beginning and the fullness of the salvation now offered to the world.