A lonely speaker imagines a wall as their only friend. Nobody else listens to them, so they turn to something equally ignored: a plain white wall that hears "constant murmurs" but never looks. The speaker feels a kinship with it, as if both were simply dropped onto the land and left there.
Midway through, the tone shifts. The speaker mentions ropes that seem to keep them from escaping, which suggests they feel trapped or restrained, whether literally or by other people's control. Then comes a whispered secret: the wall can talk, but only softly and only to them. That private bond becomes a source of strength.
The ending is defiant. Those who tied the ropes will be "locked up" as silently as sin, while the speaker and the wall go free together. The mood moves from isolation and quiet sadness to a hopeful, almost rebellious determination, with the odd friendship at its centre.