A warrior in a rain-darkened cloak sits in a wet field, seen from behind, under storm clouds and a giant planet.
The warrior keeps sitting while the rain falls. The breath stays slow even when the body is cold and wet. Strength of body here means staying put without tensing up.
Kepler-1647 b is a giant planet about the size of Jupiter that orbits two stars. It goes around them about every three Earth years. The moon and the rain are invented.
Practice
Take one minute of a cool shower, breathing slowly the whole time.