|I'm fairly certain this is not the gentleman from the song.|
Image source: Luca Cinacchio on freeimages.com.
By: We don't know.
Written in: We don't know that, either, but it was before 1760.
I have thoughts: It took me a long time to understand this song, because in my head when I was a kid I kept putting the comma in the wrong place, which as we all know changes the meaning of the phrase. As a result, I spent many years wondering how, exactly, one rested merry, and not only that, but how one could be object of this resting merry instead of the agent. I imagine I'm not the only weird kid who had this problem.
One of my favourite Christmas parodies of all time is based on this song. Keep scrolling; I stuck it at the end.
Verse: It's the rare short(ish) Christmas carol! Verse three seems the least familiar to me.
"Fear not, then," said the angel,Watch:
"Let nothing you affright;
This day is born a Savior
Of a pure virgin bright,
To free all those who trust in him
From Satan's power and might."