The Hatha Yoga Pradipika - Tapa blanda

A yogi desirous of success should keep the knowledge of Hatha Yoga secret; for it becomes potent by concealing, and impotent by exposing. The Yogi should practice Hatha Yoga in a small room, situated in a solitary place, being 4 cubits square, and free from stones, fire, water, disturbances of all kinds, and in a country where justice is properly administered, where good people live, and food can be obtained easily and plentifully. The room should have a small door, be free from holes, hollows, neither too high nor too low, well plastered with cow-dung and free from dirt, filth and insects. On its outside there should be bowers, raised platform (chabootra), a well, and a compound. These characteristics of a room for Hatha Yogis have been described by adepts in the practice of Hatha.