Origen — as excerpted in the Catena Aurea on Luke 2:8-12

“But if we would rise to a more hidden meaning, I should say, that there were certain shepherd angels, who direct the affairs of men, and while each one of them was keeping his watch, an angel came at the birth of the Lord, and announced to the shepherds that the true Shepherd had arisen. For Angels before the coming of the Saviour could bring little help to those entrusted to them, for scarcely did one single Gentile believe in God. But now whole nations come to the faith of Jesus.”