The tradition divides saucha into two hemispheres, and insists on both. Outer purity, bahya saucha, is the visible discipline: the bathed body, clean clothing, food rightly sourced and prepared, a dwelling kept in order. Classical Hindu practice elaborated this into an entire liturgy of daily washing, and the later hatha yoga manuals added the shatkarmas, six internal cleansings of the nasal passages, stomach and gut, treating the body frankly as an instrument that clogs. Inner purity, abhyantara saucha, is the invisible half: the clearing from the mind of envy, resentment, deceit and pride, described with the same vocabulary of washing and scouring. The pairing is deliberate.
Outer cleanliness without inner is the whitewashed surface the moralists of every tradition mock; inner aspiration without outer discipline dissipates, because the mind does not stay clear in a neglected body and a disordered room. Patanjali's treatment at sutras 2.40 and 2.41 gives each hemisphere its own fruit. From bodily purity comes a certain distance toward the body, a loosening of infatuation with one's own flesh and of craving for contact with others'. From mental purity comes a cascade: cheerfulness, one-pointedness, mastery of the senses and at last fitness to see the self. The order matters, the tradition says: one scrubs the vessel before pouring anything precious into it.