Bhagavad Gita: Well established in Yoga (Dhyana-yoga (Text 18 Ch 6))

Sri-bhagavan uvaca

yada viniyatam cittam
atmany evavatisthate
nisprhah sarva-kamebhyo
yukta ity ucyate tada

Meaning: When the yogi, by practice of yoga, disciplines his mental activities and becomes situated in transcendence-devoid of all material desires-he is said to be well established in yoga.

Bhagavad Gita: Well established in Yoga  (Dhyana-yoga (Text 18 Ch 6))