Suddenly a great company of the heavenly host appeared with the angel, praising God and saying, “Glory to God in the highest heaven, and on earth peace to those on whom his favor rests.” When the angels had left them and gone into heaven, the shepherds said to one another, “Let’s go to Bethlehem and see this thing that has happened, which the Lord has told us about.”

Luke 2:13-15//

The angels appeared out of nowhere, but the shepherds likely saw them go into Heaven; a foreshadow of how our Savior would appear and then ascend into Heaven. His announcement and departure mirroring one another.