11.28–33

Brendan tells the monks to eat something, after which they celebrate Mass and sleep.  They then begin (before dawn) celebration of the Daily Office / Liturgy of the Hours, with the birds joining in for at least some of the psalms.

[29] opus Deī: the service of Compline.

usque ad tertiam vigiliam noctis: “until the third watch of the night,” i.e. midnight.

[30] ad vigiliās noctis sānctae: i.e., Matins / Mattins / the night office, around one o’clock on Easter morning.

Domine, labia mea aperies: Psalm 50.17 (51.15): “O Lord, thou wilt open my lips (Domine, labia mea aperies), and my mouth shall declare thy praise.” A very common liturgical opening.

[31] omnēs avēs ālīs et ōre resonābant: the birds sing and beat their wings in response to Brendan’s intoning of the first part of Psalm 50.17 (51.15); birds and humans are praising God together. But instead of responding with the rest of this familiar verse (“and my mouth will declare your praise”), as a practicing Christian would expect, the birds sing part of a different psalm.

Laudāte Dominum ... virtūtēs eius: Psalm 148.2 “Praise ye him, all his angels! Praise ye him, all his hosts!” (Laudate eum, omnes angeli eius! Laudate eum, omnes virtutes eius!). The birds sing just this one line, for an hour.

[32] Cum autem aurōra refulsit: at the dawn service (“Prime”).

[33] Et sit splendor Dominī Deī nostrī super nōs: Psalm 89.17 (90.17): “And let the brightness of the Lord, our God, be upon us (Et sit splendor Domini, Dei nostri, super nos), and direct thou the work of our hands over us; yea, the work of our hands do thou direct.

aequālī modulātiōne et longitūdine psallendī: "with the same tune(s) and the same length(s) of time for singing psalms."

in mātūtīnīs laudibus: Matins / Mattins / the night office.