It consists of four stanzas taken from the hymn by Venantius Fortunatus, which extol the privilege of the Virgin, in whose womb the Creator of heaven and earth became incarnate.
BIBL.: H. A. Daniel, Thesaurus hymnologicus, III, Leipzig 1847, p. 321; G. G. Belli, Gli inni del Breviario tradotti, Rome 1856, p. 410; C. Albin, La poésie du Bréviaire, Lyons n.d., pp. 453-456; A. Mirra, Gli inni del Breviario romano, Naples 1947, pp. 150-61. Silvio Mattei