When the fully restrained mind rests in the Self alone, and one is free from craving for every object of desire, then one is said to be established in yoga.
Explanation
Krishna is describing to Arjuna the mark of a person who has truly achieved yoga (spiritual discipline, union). The mind, fully restrained (viniyata), rests in the Self (ātman) and no longer longs for any object of desire (kāma). Traditions differ on "Self": non-dualist readings take it as one's own true nature identical with the absolute, while devotional readings take it as the individual soul, focused on God.