Verse 53

विहरन्नपि नोद्वेगी नानन्दमुपगच्छति ।अन्तर्मुक्तमना नित्यं कर्मकर्तेव तिष्ठति

In plain words

even while he moves about amid them, he is not agitated, nor does he go to joy; his mind ever free within, he stands like a doer of action.