Legend claims the St. Gregory the Great (d. 604) listened to the very first 3 lines chanted by angels on a particular Easter morning in Rome even though he walked barefoot in a great spiritual procession and which the saint thereupon additional the fourth line: “Ora Professional nobis Deum. Alleluia.” https://vita-pro-nobis66421.mybuzzblog.com/10782242/a-secret-weapon-for-vita-pro-nobis