Peace starts in the inner being

The peace starts in the inner being—it is spiritual and psychic but it overflows the outer being—when it is there in the activity, it means either that the ordinary restless mind, vital, physical has been submerged by the flood of the inner peace or, at a more advanced stage, that they have been partially or wholly changed into thoughts, forces, emotions, sensations which have in their very stuff an essence of inner silence and peace.

Ref: Letters on Yoga Vol. II