From the Christmas Carol Songbook:
cantorion.org/ ... tmas-Carol-Songbook-Voice-SATB

Lyrics:
Break forth, O beauteous heavenly light,
And usher in the morning;
O shepherds, shrink not with afright,
But hear the angel’s warning.
This Child, now weak in infancy,
Our confidence and joy shall be,
The power of Satan breaking,
Our peace eternal making.