Legend suggests the St. Gregory The nice (d. 604) listened to the initial three lines chanted by angels on a certain Easter early morning in Rome even though he walked barefoot in a fantastic religious procession and which the saint thereupon included the fourth line: “Ora Professional nobis Deum. Alleluia.” https://vitapronobis10864.vblogetin.com/36743663/a-review-of-vita-pro-nobis