Legend claims the St. Gregory the Great (d. 604) listened to the very first 3 lines chanted by angels on a particular Easter early morning in Rome although he walked barefoot in an awesome religious procession and which the saint thereupon additional the fourth line: “Ora Professional nobis Deum. Alleluia.” https://dores-nos-nervos95161.mybjjblog.com/not-known-facts-about-vita-pro-nobis-44322765