Grounded and settled describes an inner steadiness, the awakened conviction rooted so deep in the body that the shifting weather of the lower mind cannot pull it loose. To be moved away is to let the currents of ordinary thought carry the center off its foundation. Every creature under heaven is every living faculty within a person beneath the crown of the head, and to each of them the good news has already been sounded.
The steady state holds when the higher understanding is planted firmly enough in a person that daily agitation no longer uproots it. Heaven here is the head, the region above, and the message has reached down into every part of the being that lives below it.
Heaven: the head and its high crown, the upper region of consciousness in a person
Creature under heaven: every living faculty of the body beneath the head, each part that can receive the inner word