Prayers before and after the Divine Office

Prayer to be said before Divine Office

APERI, Dómine, os meum ad benedicéndum nomen sanctum tuum: munda quoque cor meum ab ómnibus vanis, pervérsis et aliénis cogitatiónibus; intelléctum illúmina, afféctum inflámma, ut digne, atténte ac devóte hoc Offícium recitáre váleam, et exaudíri mérear ante conspéctum divínæ Majestátis tuæ. Per Christum Dóminum nostrum. Amen. O LORD, open Thou my mouth, that I may bless Thy holy name; cleanse my heart too from all vain, evil, or wandering thoughts. Enlighten mine understanding, kindle mine affections, that I may be able to say this Office meetly with attention and devotion, and may deserve to be heard before the presence of Thy divine Majesty. Through Christ our Lord. Amen.
Dómine, in unióne illíus divínæ intentiónis, qua ipse in terris laudes Deo persolvísti, has tibi Horas (vel hanc tibi Horam) persólvo. O Lord, in union with that divine intention wherewith Thou Thyself, while on earth, didst offer praises unto God, I offer these hours (or this hour) unto Thee.

Prayer to be said after Divine Office

To those who, after the Divine Office, shall on their knees recite with devotion the following prayer, Pope Leo X granted indulgence in respect of those shortcomings and faults which they may have committed through human frailty while saying Office.
SACROSÁNCTÆ, et indivíduæ Trinitáti, crucifíxi Dómini nostri Jesu Christi humanitáti, beatíssimæ et gloriosíssimæ sempérque Vírginis Maríæ fœcúndæ integritáti, et ómnium Sanctórum universitáti sit sempitérna laus, honor, virtus et glória ab omni creatúra, nobísque remíssio ómnium peccatórum, per infiníta sæcula sæculórum. R. Amen. TO the most holy and undivided Trinity, to the manhood of our crucified Lord Jesus Christ, to the fruitful virginity of the most blessed and glorious Mary, ever a Virgin, to the entire assembly of the saints, be ascribed everlasting praise, honor, power, and glory, by every creature; and to us be granted the remission of all our sins, world without end. R. Amen.
V. Beáta víscera Maríæ Vírginis, quæ portavérunt ætérni Patris Fílium. V. Blessed is the Virgin Mary’s womb, which bore the Son of the Everlasting Father.
R. Et beáta úbera quæ lactavérunt Christum Dóminum. R. And blessed are the paps that gave suck to Christ our Lord.
Et dicitur secreto Pater noster et Ave María. Then is said secretly an Our Father and a Hail Mary.