Hatha Yoga Pradipika – Causes of success in sadhana
Utsahat sahasad dhairyat tattvajnanas cha nischayat/
Janasangghaparityaghat shadbhir yogah prasiddhyati// (Chapter -1, Verse -16).
Enthusiasm, perseverance, discrimination, strong faith, courage, avoiding the company of common people, are the (six causes) which bring success in Hatha Yoga. (Chapter -1, Verse – 16).