The motivation for any human action in the outer world is to achieve better satisfaction and contentment. The man of perfection does not depend on external objects for his happiness. He finds his joy, bliss and contentment in his own Divine experience. When he has already achieved satisfaction and contentment, no more desires arise in him. Where there are no desires there is no action. Such a realized man is a person endowed with Self-Knowledge. He has no worldly duties to perform. He is the knower of Brahman.

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Tu, but; that manavah, man, the sannyasin, the man of Knowledge, steadfast in the knowledge of the Self; yah, who; atmaratih eva syat, rejoices only in the Self-not in the sense objects; and atma-trptah, who is satisfied only with the Self-not with food and drink; and is santustah, contented; eva, only; atmani, in the Self; tasya, for him; na vidyate, there is no; karyam, duty [Duty with a view to securing Liberation.] to perform. [Rati, trpti and santosa, though synonymous, are used to indicate various types of pleasures. Or, rati means attachment to objects; trpti means happiness arising from contact with some particular object; and santosa means happiness in general, arising from the acquisition of some coveted object only.]

All people surely feel contened by acquiring an external thing. But this one, without depending on it, remains contented only with the Self; thta is to say, he remains detached from everything. The idea it that, for a man who is such a knower of the Self, there is no duty to undertake.