Chapter 15 of the Rule of St. Benedict:
The Times to say "Alleluia"
From holy Easter until Pentecost without interruption
let "Alleluia" be said
both in the Psalms and in the responsories.
From Pentecost to the beginning of Lent
let it be said every night
with the last six Psalms of the Night Office only.
On every Sunday, however, outside of Lent,
the canticles, the Morning Office, Prime, Terce, Sext and None
shall be said with "Alleluia,"
but Vespers with antiphons.
The responsories are never to be said with "Alleluia"
except from Easter to Pentecost.
In Chapter 15, St. Benedict regulates the times for saying Alleluia, which means “Praise the Lord!” So why is Benedict so concerned about limiting the use of such a magnificent word? It is because Benedict knew the tremendous meaning Alleluia signifies when it is used in a proper time and place. For instance, Benedict was probably very aware that the only time Alleluia is used in the New Testament is chapter nineteen of the Book of Revelation (verses: 1, 3, 4, 6), the Wedding Feast of the Lamb, the triumphal banquet where all the souls redeemed by Christ unceasingly Praise God for His Salvation. For Benedict, life at the monastery was supposed to be a foretaste of this life in Heaven, this Wedding Feast of the Lamb. Therefore, in anticipation of this Heavenly Life, Benedict might have said, “If we will be unceasingly acclaiming Alleluia when we are in Heaven, how could we not also acclaim it while we are still exiles here on earth?” Clearly Benedict knew and loved the beauty of this word! However, he also recognized that we lowly and sinful exiles have yet to fully attain this Blessed Life. Therefore, the most appropriate times for saying Alleluia are related to the times we most vividly remember the Resurrection: the entire season of Easter, Vigils, that is, early in the morning, the time of day that Christ rose from the dead, and Sunday, the day of Resurrection!