योगस्थः कुरु कर्माणि सङ्गं त्यक्त्वा धनञ्जय।
सिद्ध्यसिद्ध्योः समो भूत्वा समत्वं योग उच्यते॥48॥
yoga-sthaḥ kuru karmāṇi saṅgaṁ tyaktvā dhanañ-jaya |
siddhy-asiddhyoḥ samo bhūtvā samatvaṁ yoga ucyate ||48||
Do all your acts, but remaining established in yoga, leaving the usual delusional clinging. Preserve an even attitude to fruition and non-fruition of whatever you do. Such evenness is defined as yoga.
Here, Krishna gives the practical formula for performing action without getting entangled: be established in yoga. Yoga here means equanimity, a balanced state of mind. By abandoning attachment to the results—whether you succeed or fail—and performing your duty with a steady mind, you are practicing true yoga. This evenness is the secret to spiritualizing all of life's activities.
References
Watch the discourse on this verse.