Shankaracharya's commentary, trans. Alladi Mahadeva Sastry (1897)
[1]When the completely controlled mind rests in the Self alone, free from longing for all desires — then one is called yukta.
BG 6.18
यदा विनियतं चित्तमात्मन्येवावतिष्ठते | निःस्पृहः सर्वकामेभ्यो युक्त इत्युच्यते तदा ||१८||
yadā viniyataṃ cittam ātmany evāvatiṣṭhate | niḥspṛhaḥ sarvakāmebhyo yukta ityucyate tadā || 18 ||
"When the completely controlled mind rests serenely in the Self alone, free from all desire-pull — that is called yoga."
6 translations · all pre-1928 or released to public domain · sources
When the completely controlled mind rests in the Self alone, free from longing for all desires — then one is called yukta.
When the completely controlled mind rests serenely in the Self alone, free from longing after all desires, then is one called steadfast in the Self.
When the controlled mind comes to rest within the Self, freed from all longing after desires — then is one said to be harmonised.
When the mind, well controlled, is fixed upon the Self alone, without longing after desires, then is the man called concentrated.
When the mind, quite dammed from wish and will, abides within the Self alone — then, careless of all else, they call that man Yoked.
When the restrained mind remains fixed in the Self only, then is the man, without longing for all objects of desire, said to be in concentration.