Agnus Dei Meaning: "Lamb of God" and the Fraction at Mass

The "Agnus Dei" — Latin for "Lamb of God" — is the chant sung (or said) as the priest breaks the consecrated host, just before Communion: "Lamb of God, you take away the sins of the world, have mercy on us… grant us peace." In this session of The Mass Explained, Dr. Brant Pitre traces the prayer to its scriptural source — John the Baptist's cry, "Behold, the Lamb of God, who takes away the sin of the world!" (John 1:29) — and to "the breaking of the bread" by which the risen Jesus was recognized at Emmaus (Luke 24) and by which the early Church celebrated the Eucharist (Acts 2:42). He follows the Agnus Dei through the tradition — Pope St. Sergius I, who added it to the Mass in the seventh century — and unfolds the mystical meaning of the "fraction" and "commingling" (the small piece of the host placed in the chalice) as signs of Christ's Passover sacrifice and his Resurrection, drawing on William Durand and St. Robert Bellarmine.

Key passages & sources examined: John the Baptist's proclamation (John 1:29); the road to Emmaus (Luke 24:30–31); "the breaking of the bread" in the early Church (Acts 2:41–42); "Christ our Passover" (1 Corinthians 5:7); Pope St. Sergius I and Ordo Romanus I; and William Durand and St. Robert Bellarmine on the fraction and commingling.