Surely someone has made this observation before. I just wasn't there for that particular sermon...
The infant Jesus being laid in a manger?
A manger is a container for food.
In John 6:51, Jesus said, "I am the living bread that came down from heaven. If anyone eats of this bread, he will live forever. And the bread that I will give for the life of the world is my flesh."
Verse 58: "This is the bread that came down from heaven, not like the bread the fathers ate [manna] and died. Whoever feeds on this bread will live forever."
He took on flesh for the purpose of sacrificing that same flesh—for our sakes.
That's why the Father made sure the Son was born in a barn... so His first bed would symbolize His purpose in coming.
[Translation: English Standard Version]