The edition of this motet text is based on Librone 1 (ff. 169v–170r), where it was copied by Scribe A, who made no copying mistakes.
According to the loco rubric, this last motet of the cycle was sung during the Deo gratias, a chant that resounded at the end of the mass. Above all, this motet is interesting with regard to the technique of mixing different genres of liturgical poetry in one piece. At least three different liturgical genres were used as sources for the text: antiphons, sequences, and prayers. The first section of the text (‘Da pacem ... deus noster’) is an antiphon mostly associated with the votive Suffragium pro pace or the Feast of the Holy Maccabees,^[1] but it is also used as a prayer in books of hours, for instance in a fifteenth-century book of hours from Lille (Lille, Bibl. municipale, MS 14 [a.c.69]), where it is introduced by the rubric: ‘Say this prayer after you receive the peace’ (‘Postea recipias pacem dic’) or in a fifteenth-century book of hours following the use of Rome, now in Paris (Bibl. nationale de France, MS lat. 10561).^[2] The second section (‘Ave ... serena’) is drawn from a Marian sequence (AH 54, No. 216, pp. 337–40, st. 1–2), just like the last section (‘In honore ... plena gratia’: AH 39, No. 70, pp. 67–68, st. 1a–b). The third section of the text (‘Ecce ... tuum’) corresponds to a line from the Gospel of Luke (Luke 1: 38) and is used as an antiphon and versicle for the feast of the Annunciation or during the Christmas season.^[3]

^[1] See http://cantusindex.org/id/002090.

^[2] See Giacomo Baroffio, ‘Corpus italicum precum: Materiali per una storia del sentimento religioso in Italia’, http://www.hymnos.sardegna.it/iter/iterliturgicum.htm.

^[3] See http://cantusindex.org/id/002491.