From Patanjali’s sutras Saucha makes up the first of the Niyamas.  I should note that in traditional context, Saucha is actually one of the 10 Yamas.

Saucha means cleanliness, not only within the body, but within ones environments and between relationships of individuals.  It is said that ones surroundings reflect the energetic organization that exists on a spiritual level around an individual, or group.  Physical cleanliness is simply a manifestation of a spiritual state of being.