Legend states the St. Gregory The nice (d. 604) listened to the very first a few traces chanted by angels on a specific Easter morning in Rome while he walked barefoot in a great spiritual procession and that the saint thereupon extra the fourth line: “Ora pro nobis Deum. Alleluia.” https://vita-pro-nobis65420.qowap.com/90589616/vita-pro-nobis-can-be-fun-for-anyone