Legend suggests the St. Gregory The good (d. 604) heard the first 3 lines chanted by angels on a specific Easter morning in Rome though he walked barefoot in an incredible spiritual procession and that the saint thereupon extra the fourth line: “Ora pro nobis Deum. Alleluia.” This Marian hymn https://vitapronobis87531.blogozz.com/30544610/the-best-side-of-vita-pro-nobis