This is not one line but when I first heard this song I knew Plant was really developing as a lyricist. It would be difficult to choose one line from this song. The whole thing works together so well.
Her face is cracked from smiling, all the fears that she's been hiding
And it seems that pretty soon, everybody's gonna know
And her voice is sore from shouting, cheering winners who are losing
And she worries if their days are few and soon they'll have to go
She hears them talk of new ways to protect the home she lives in
Then she wonders what it's all about when they break down the door.
Her name is brown or white or black You know her very well,
You hear her cries of mercy as the winners toll the bell.
Oh, there is a train that leaves the station heading for your destination
But the price you pay to nowhere has increased a dollar more Yes, it has! And if you walk you're gonna get there
Although it takes a little longer And when you see it in the distance you will wring your hands and moan