Definition - What does Saucha mean?
Saucha is the first of the five niyamas (personal observances), which form the second limb of yoga as described in "The Yoga Sutras of Patanjali." The Sanskrit term can be literally translated as "purity," "cleanliness" and "clearness," and it covers the cleanliness of body as well as the purity of mind. This niyama reminds one to live a healthy life and keep the body and mind pure. Healthy diet, personal hygiene and self-care are also considered saucha.
Practice of saucha starts with the external environment and keeping the surroundings clean. It also includes purity of bodies from both outside and inside, relationships and speech.
Yogapedia explains Saucha
There are several examples of the experience of saucha, both in yoga and in everyday life. In yoga practice, practitioners are encouraged to keep their bodies, yoga props and the space where they practice clean. It helps to improve concentration and awareness. Saucha of speech is also recommended during a yoga class. Being quiet helps to deepen the practice and shows respect to the teacher and/or to fellow yogis.
Saucha off the mat encourages one to keep his/her close surroundings clean. It is recommended to start with the closest small area, find the benefit and then explore further. The saucha of speech off the mat teaches to control what is said and how it is said and trying not to say negative or harmful things. The saucha of thoughts in everyday life teaches one to keep the mind calm, centered and peaceful.
Yogis use different poses, mudras, pranayama and mantras to incorporate saucha into their own lives and practice.