Hathayoga Pradipika

In Light on the Yoga Sutras of Patanjali, by B.K.S. Iyengar he writes about the Hathayoga Pradipika written by Svatmarama. 
He says that Svatmarama explains that the body, being inert, tamasic, is uplifted to the level of the active, rajasic, mind through asana and pranayama with yama and niyama.  When the body is made as vibrant as the mind, through study, svadhyaya and through practice and repetitions, abhyasa, both mind and body are lifted towards the noumenal state of sattva guna.  From sattva guna the sadhaka follows Isvara pranidhana to become a gunatitan (free from gunas).

Namaste.
Pamela Nelson
www.plnyoga.vpweb.com