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
The surgeon operates the same way on the routine gall bladder and on the case that will be written up. Same care, same hands, same order of moves. The difference in stakes is real, and it is not allowed into the room.
Going deeper
Yoga is not defined here as union with God, or as stilling the mind, or as any technique at all. It is defined as a quality of the person acting: being the same across outcomes. Samatvaṃ yoga ucyate - evenness is called yoga.
What makes that useful is how narrow it is. 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 the sticking - is the mechanism. The sticking is what makes an outcome yours before it has even 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 reach by working correctly. It is where you stand before you begin, which is why 2.47 had to come first.