Chapter IV · Śloka 15
एवं ज्ञात्वा कृतं कर्म पूर्वैरपि मुमुक्षुभिः ।
कुरु कर्मैव तस्मात्त्वं पूर्वैः पूर्वतरं कृतम् ॥
कुरु कर्मैव तस्मात्त्वं पूर्वैः पूर्वतरं कृतम् ॥
evaṃ jñātvā kṛtaṃ karma pūrvair api mumukṣubhiḥ |
kuru karmaiva tasmāt tvaṃ pūrvaiḥ pūrvataraṃ kṛtam ||
kuru karmaiva tasmāt tvaṃ pūrvaiḥ pūrvataraṃ kṛtam ||
Knowing this, the ancient seekers of liberation also performed action. Therefore, do you perform action as the ancients did in former times.
Krishna appeals to the authority of lineage: the liberated sages of old acted in the world even after realisation, and their example validates Arjuna's path of action. Renunciation of action is not the ancient way.