योगस्थः कुरु कर्माणि सङ्गं त्यक्त्वा धनञ्जय।सिद्ध्यसिद्ध्योः समो भूत्वा समत्वं योग उच्यते॥
yoga-sthaḥ kuru karmāṇi saṅgaṃ tyaktvā dhanañjayasiddhy-asiddhyoḥ samo bhūtvā samatvaṃ yoga ucyate
Word by word
The verse says
Stand in yoga and do your work, Arjuna, letting go of the holding-on. Be the same whether it succeeds or fails. That evenness is what yoga means.
In plain words
Krishna defines the word he has been using.
Do the work. Drop the attachment. Be the same either way.
And then: that evenness is yoga. Not the posture, not the breathing. This.
Where you've felt this · in health
A surgeon operates the same way on the routine case and the one that will make the journals. Same care, same hands. The difference in stakes is real and it is not allowed into the room.
Going deeper
Samatvaṃ yoga ucyate — evenness is called yoga. It is one of the Gita's two great definitions, and the other is in the next verse but one.
What makes it useful is how narrow it is. Yoga is not defined here as union with God, or as stilling the mind, or as any technique. It is defined as a quality of the person acting: being the same across outcomes.
That means it is testable, and testable in ordinary life. You do not need a quiet room. You need a situation with an outcome, and you can find out whether you are the same on both sides of it.
Saṅgaṃ tyaktvā — having let go of attachment — is the mechanism. Saṅga is the sticking, the clinging that makes an outcome yours before it has arrived.
And notice the order of the sentence. Yoga-sthaḥ kuru karmāṇi — be established in yoga, then act. The evenness is not a result you achieve by working correctly. It is where you stand before you begin. Which is why 2.47, the verse just before, had to come first.