The poem speaks in the voice of a wire brush, or speaks to it, and imagines what its life is like. The brush has no feet, yet its bristles act like countless tiny legs, so every stroke becomes a kind of walking. The opening calls that walking a penance, a punishment that feels earned, and the corrosive rain suggests the rust and wear the brush is built to fight.
The middle turns to something more human. Pacing back and forth is what we do when we're anxious and can't sit still, and the poem says that repetition can harden into discipline. As the ground warms and gleams "like an interrogator," the scene starts to feel like a questioning. The line "You confess, confess, confess" mimics the brush's scraping rhythm while hinting at guilt and pressure.
The ending is quiet and a little bleak: the tracks are covered with thin brown dust, which suggests rust scrubbed away, or traces fading. The mood is restless, stern, and weary, with a dry humor under it.