Beauty, gracefulness, strength, and adamantine hardness is the perfection of the body.
This verse is in relation to the mastery of the five elements where one attains to the perfection of the body. The body is composed by and of the five elements with the Life-force (Prana) animating it.
Mastery of the five elements together with the stabilizing of the Life-force through a controlled and focused mind will create the perfection of the body which reflects the light of inner beauty and becomes full of grace in its expression, is filled with and contains the Life-force exhibiting strength and enduring resilience (adamantine hardness).
The human body is the Temple and temporary abode of the Divine built by Mother Nature. The building blocks of this human temple are the five elements which are cemented energetically by the Cosmic Life-force, the Cosmic Prana. Maintaining and perfecting this human temple of ours means that we can meet the Divine face to face (our ‘original face’) within our own self, the Inner Sanctum Sanctorum of our breathing and beating heart.