Listen to the Sanskrit Recitation of Hatha Yoga Pradipika, Chapter 2 Verse 21. Recitation by Sukadev Bretz of Yoga Vidya. Full text (Devanagari, Roman/English Transliteration): http://schriften.yoga-vidya.de/hatha-yoga-pradipika/2-kapitel-vers-21. The Hatha Yoga Pradipika is the most important classical text of Hatha Yoga, probably written in the 14. Century CE.