The Rule of St. Benedict

From holy Easter until Pentecost let the Alleluia be said without intermission, both with the psalms and with the responsories; but from Pentecost until the beginning of Lent let it be said every night at the nocturns with the six latter psalms only. However, on all Sundays outside of Lent, let the canticles, Lauds, Prime, Tierce, Sext, and None be said with Alleluia. Let Vespers, however, be said with the antiphon; but let the responsories never be said with Alleluia, except from Easter to Pentecost.