The fist can break stones.
3 seconds sound clip from the Born Invincible (1978) movie soundboard.
You can hear this line at 00:01:36 in the DVD version of the movie.
Quote context
[...]
- Out of that, more weight is concentrated in the feet. Promotes stability.
- The result is fantastic strength and control.
- Every ounce of the body's strength can be transformed instantaneously to one single part.
- Out of very few who achieve... become like steel. Their feet steady as rock.
- The character becomes volatile to match the body's speed.
- And the body,while retaining its suppleness, becomes impenetrable and impervious to weapons.
[...]