The fifth day within the Octave of St. Lawrence is of semi-double rite and the liturgical colour of the day is red.
At Mattins the invitatory is as on the feast of St. Lawrence, Beatus Laurentius Christi Martyr triumphat coronatus in caelis: * Venite adoremus Dominum. The Office hymn is Deus tuorum militum. In the first nocturn the antiphons Quo progrederis etc are sung with psalms 1, 2 & 3. The lessons are those of occurring scripture for the Saturday of the second week of August. The first lesson begins Melius est a sapiente... and continues until ...stulta est hujusmodi interrogatio. In the modern Breviary the lessons for Saturday begin with the first verse of Ch. 7 of Ecclesiastes but this was read as the third lesson yesterday in the usus antiquior with today's lessons beginning at verse 6 of Ch. 7. The second lesson begins Utilior est sapientia... (v.12) and continues until the end of v. 16, ...vivit tempore in malitia sua. Part of this text can be found half-way through the modern third lesson. The third lesson begins Noli esse justus... and continues until ...maledixisti ejus. vv. 17-23. This text is entirely absent from the modern books. In the second nocturn the antiphons Beatus Laurentius etc are sung with psalms 4, 5 & 8. The lessons are from a sermon of St. Maximus. These are longer than those found in the modern (pre-1911) editions. In the third nocturn the antiphons Strinxerunt corporis are sung with psalms 14, 16 & 20. The homily is taken from St. Chrysostom's 65th homily on St. John's Gospel. The ninth lesson is of the Vigil. The Gospel fragment is from St. Luke (Lk 11:27-28) containing the passage wherein "a certain woman from the crowd, lifting up her voice, said to him: Blessed is the womb that bore thee, and the paps that gave thee suck" to which the LORD responds "Yea rather, blessed are they who hear the word of God, and keep it." St. Augustine's homily praises the Virgin for doing will of the Father and St. Augustine has the LORD say: "Hoc est dicere: Et mater mea, quam appellatis felicem, inde felix, quia verbum Dei custodit: non quia in illa Verbum caro factum est, et habitavit in nobis: sed quia custodit ipsum Verbum Dei, per quod facta est, et quod in illa caro factum est." The Te Deum is sung.
At Lauds the antiphons Laurentius ingressus est martyr etc are sung with psalms 92, 99, 62-66, Benedicite & 148-149-150. The Office hymn is Martyr Dei, qui unicum. After the collect of the Octave a commemoration is sung of the Vigil: the antiphon on the Benedictus is of the Saturday, Illuminare Domine etc., and the V&R Repleti sumus etc and Exsultavimus etc., again both from the Saturday; the collect is proper to the Vigil. After the commemoration of the Vigil a commemoration is sung of St. Eusebius.
At Prime and the Hours the antiphons from Lauds, Laurentius etc., are sung. At Prime the Dominical preces are omitted because of the Octave and the lectio brevis is Potens est autem.
Mass, of the Vigil, is sung after None. Violet dalmatic and tunicle are used. The second collect is of the Octave, the third collect is of St. Eusebius and the Common Preface is sung.
In the afternoon first Vespers are sung of the great feast of the Assumption. The liturgical colour changes to white and the antiphons Assumpta est Maria etc are sung with psalms 109, 112, 121, 126 & 147. The chapter is from Ecclesiasticus, In omnibus requiem etc., and the Office hymn Ave, Maris stella. After the collect of the feast a commemoration is sung of the Sunday, the antiphon on the Magnificat is Omnis sapientia for the Saturday before the third Sunday of August. At Compline Te lucis is sung to the tone for feasts of the BVM and with the Doxology Gloria tibi Domine, Qui natus es de Virgine, Cum Patre et Sancto Spiritu, In sempiterna saecula.