AGNUS DEI

During the recital of the “Agnus Dei” the priest strikes his breast three times in humble sorrow for his sins, saying the two first times, “Lamb of God who takest away the sins of the world, have mercy on us”; and the third time, “Lamb of God who takest away the sins of the world, grant us peace.” In Masses for the dead the form is, “Lamb of God who takest away the sins of the world, grant them rest”; this is repeated twice, and the third time is said, “Lamb of God who takest away the sins of the world, grant them eternal rest”; but the breast is not struck at all at these Masses, inasmuch as they concern the dead and not the living. The expression “Lamb of God,” as applied to our Lord, is taken from Holy Scripture, where we find it frequently occurring. From the relations between our Saviour and the Paschal lamb of the ancient law, a preference was given to the use of it in early days.

Before the time of Pope Sergius I. (A.D. 687 to 701), the chanting of the “Agnus Dei” was solely confined to the choir, but by a decree of this pontiff it was also extended to the clergy. This is the explanation that Mabillon gives; and it seems in accordance with what the Pontifical Book states about the pontiff named, for in its fourteenth chapter the following occurs: “He ordained that at the time of the fraction of the Body of the Lord ‘Agnus Dei qui tollis peccata mundi, miserere nobis,’ should be sung by the clergy and people” (Romsee, p. 281). It is for this reason that Pope Sergius is generally accredited with the introduction of the “Agnus Dei” into the Mass. But that it existed long before his time may be seen from the Sacramentary of Pope Gregory the Great.

The number of times, however, that it was to be said varied very considerably. Sometimes it was said but once, and this was all that Pope Sergius ordered in his decree concerning it. At other times it used to be kept up until the entire ceremony of the fraction of the sacred Bread had been gone through with; whence it was sung once, twice, three times—as often, in fact, as was necessary. Its double repetition was very frequent in the eleventh century; and Belethus (chap. 48.) alludes to its triple repetition in the century following. The same may be seen in the Missals printed at that period, from which it may be fairly inferred that the present discipline dates. Nor must we omit to mention that the celebrant did not say the “Agnus Dei” at all when first introduced, but only the choir. When the duty became incumbent on the priest also it is not easy to determine. According to Romsee, the pope used to say it in his Mass about the fourteenth century. Very likely it became obligatory on priests in general about this period also. Another variation that respected its recital was that in some places it used to be said once before the Preface and twice at the place where it is now recited (Romsee, p. 282).

The words “grant us peace,” added to the last repetition, instead of “have mercy on us,” have not been always in use, nor is it customary now to say them in the church of St. John Lateran at Rome. According to very creditable authorities (see Bona, p. 358), they were first introduced by directions received from the Mother of God, who appeared one day to a certain carpenter as he was felling trees in the forest, and gave him a medal with the image of our Lord upon one side, and the inscription, “Lamb of God, who takest away the sins of the world, grant us peace,” on the other. The Blessed Virgin commanded the carpenter to show this medal to the bishop of the place, with the request that others might be made in imitation of it and be reverently worn, in order that God might restore peace to the Church of those days. The addition soon found its way into the Mass, where it has been retained ever since.