Legend claims the St. Gregory the Great (d. 604) read the very first a few lines chanted by angels on a particular Easter morning in Rome even though he walked barefoot in an excellent spiritual procession and that the saint thereupon additional the fourth line: “Ora Professional nobis Deum. Alleluia.” https://doresnosnervos94949.widblog.com/86164074/vita-pro-nobis-an-overview