shucau deshe pratishthapya sthiram asanam atmanah
naty-ucchritam natinicam cailajina-kushottaram
tatraikagram manah kritva yata-cittendriya-kriyah
upavishyasane yunjyad yogam atma-vishuddhaye
Establishing a seat in a clean environment that is not too high or too low, a yogi should cover his sitting place with kusha grass, a deerskin and a cloth. Sitting on that seat, fixing his mind on one point and controlling all the activities of the mind and senses, he should practice yoga to purify himself.