The Octave Day of St. Lawrence is of double rite and its liturgical colour is red. The XIII Sunday after Pentecost and the third Sunday of August is commemorated in the Office and Mass. Today is also the Sunday within the Octave of the Assumption.
At Vespers yesterday afternoon the antiphons Laurentius ingressus est martyr etc were sung with psalms from the Common of Apostles, Pss. 109, 110, 111, 112 & 116. The Office hymn was Deus, tuorum militum sung with the Doxology of the Incarnation, Gloria tibi Domine etc. The chapter, antiphon on the Magnificat and collect were proper, the rest of the Office from the Common of Martyrs. After the collect of the feast (which is proper to the Octave Day) commemorations were sung of the Sunday (the antiphon being Omnis sapientia for the Saturday before the third Sunday of August) and of the Octave of the Assumption. The Suffrages were omitted. At Compline Te lucis was sung with the Doxology Gloria tibi Domine etc and the Dominical preces were omitted.
At Mattins the invitatory is Beatus Laurentius, Christi Martyr, triumphat coronatus in caelis: Venite, adoremus Dominum and the Office hymn is, again, Deus, tuorum militum, sung with the Doxology of the Incarnation. In the first nocturn the antiphons Quo progredis etc are sung with psalms 1, 2 & 3. The lessons, for the Sunday, are the Incipit of the Book of Wisdom. The first lesson is longer than that found in the post-Clementine editions. It continues Spiritus enim ... superveniente iniquitate. The second lesson begins Benignus est enim and continues until quod mentitur occidit animam - what is now the end of third lesson. The text of the third lesson is not found in the post-Clementine Nolite zelare ...qui sunt ex parte illius, vv. 12-16. The responsories are from the feast. In the second nocturn the antiphons Beatus Laurentius etc are sung with psalms 4, 5 & 8. The lessons are from the writings of St. Augustine on St. John. These are the same as those found in the later edtions. In the third nocturn the antiphons Strinxerunt etc are sung 14, 16 & 20. The lessons in the third nocturn are from a sermon of St. Chrysostom on St. John's Gospel. These are marginally longer than those found in the later books. Today the eighth and ninth lessons of the Octave Day are read together to form an extended eighth lesson of the day and the ninth lesson is formed of the three lessons of the Sunday's homily from St. Augustine on St. Luke's Gospel. These are substantially longer than those found in the post-Clementine editions with lessons seven and eight (of the Sunday) comprising of the text of the later three lessons. The ninth lesson is absent from the post-Clementine editions. The Te Deum is sung.
At Lauds the antiphons Laurentius ingressus est martyr etc are sung with psalms 92, 99, 62-66, Benedicite and 148-149-150. The Office hymn is Martyr dei. After the collect of the Octave Day commemorations are sung of the Sunday and of the Octave of the Assumption. The Suffrages are omitted.
At Prime and the Hours the antiphons from Lauds, Laurentius etc., are sung with the festal psalms. At Prime the Dominical preces are omitted and the lectio brevis is Potens est autem. The hymns are sung with the Doxology of the Incarnation.
Mass is sung after Terce. The Gloria is sung, the second collect is of the Sunday, the third collect is of the Octave of the Assumption. The Credo is sung, the preface is of the Blessed Virgin and the last Gospel is of the Sunday.
At second Vespers the antiphons Laurentius etc are again sung with psalms 109, 110, 111, 112 & 115. . After the collect of the feast commemorations are sung of the Sunday, of the Octave of the Assumption and of St. Agapitus. The Suffrages are omitted as are the Dominical preces at Compline.