4:15  

एवं ज्ञात्वा कृतं कर्म पूर्वैरपि मुमुक्षुभिः ।
कुरु कर्मैव तस्मात्त्वं पूर्वैः पूर्वतरं कृतम् ॥४-१५॥

ewaM dnyaatwaa kRRitaM karma poorwairapi mumukShubhiH ।

kuru karmaiwa tasmaattwaM poorwaiH poorwataraM kRRitam ॥४-१५॥

Source: Automatic ITRANS Transliteration

Knowing this, the ancients performed actions, even those desiring liberation.
Therefore, you must perform actions performed in the past by those ancients.

Source: Milind S. Pandit

The ancient seekers of liberation also performed their duties with this understanding. Therefore, you should do your duty as the ancients did.

Source: The Bhagavad-Gita: The Sacred Song

All the liberated souls in ancient times acted with this understanding and so attained liberation. Therefore, as the ancients, you should perform your duty in this divine consciousness.

Source: Bhagavad Gita As It Is