And the Mountains in Reply

Angels we have heard on high,
sweetly singing o'er the plains,
And the mountains in reply,
echoing their joyous strains:
Glory be to God in the highest!

The mountains? The song says "the mountains." The mountains are singing too? I always used to think that the mountains were just the big wall for the angels' song to bounce back from. That's what an echo is, right?

But ...
Romans 8 tells us that the whole creation eagerly waits for the revealing of the sons of God. The creation groans and labors, waiting for deliverance from the futility to which it was subjected.
And ...
Jesus told the grumbling Pharisees that if the children were not praising Him on Palm Sunday, then the rocks themselves would cry out in praise.
And ...
in Psalm 98 (and others) we pray things like: "Let the hills be joyful together before the Lord."

And the mountains in reply,
echoing their joyous strains!