4.20 Engaged, and accumulating nothing Krishna speaks

त्यक्त्वा कर्मफलासङ्गं नित्यतृप्तो निराश्रयः
कर्मण्यभिप्रवृत्तोऽपि नैव किञ्चित्करोति सः

tyaktvā karma-phalāsaṅgaṁ nitya-tṛipto nirāśhrayaḥ
karmaṇyabhipravṛitto ’pi naiva kiñchit karoti saḥ

Having given up attachment to the fruit of action, always content, dependent on nothing, such a person does not accumulate even while fully engaged.

Explanation

Fully engaged, and accumulating nothing.

Having given up attachment to the fruit, always content, dependent on nothing — such a person does not accumulate even while fully engaged.

That last clause is the whole promise of the chapter. Not less activity: the same activity leaving no residue.