The Hatha Yoga Pradipika by Swami Swatmarama

The Hatha Yoga Pradipika is a classical text describing Hatha Yoga. It is the oldest surviving text on Hatha Yoga. Swami Swatmarama, a disciple of Swami Goraknath, wrote the text, drawing upon previous texts and his own experiences. While the text describes asanas (postures), purifying practices (shatkarma), mudras (finger and hand positions), bandhas (locks), and pranayama (breath exercises), it also explains that the purpose of Hatha Yoga is the awakening of kundalini (subtle energy), advancement to Raja Yoga, and the experience of deep meditative absorption known as samadhi.