Bhagavad Gita: Practice Yoga with determination and faith (Dhyana-yoga (Text 24 Ch 6))

Sri-bhagavan uvaca

sa niscayena yoktavyo
yogo 'nirvinna-cetasa
sankalpa-prabhavan kamams
tyaktva sarvan asesatah
manasaivendriya-gramam
viniyamya samantatah

Meaning: One should engage oneself in the practice of yoga with determination and faith and not be deviated from the path. One should abandon, without exception, all material desires born of mental speculation and thus control all the senses on all sides by the mind.

Bhagavad Gita: Practice Yoga with determination and faith  (Dhyana-yoga (Text 24 Ch 6))