4.17 Hi, for; there is something boddhavyam, to be known; api, even; karmanah, about action enjoined by the scriptures; and there is certainly something to be known vikarmanah, about prohibited action; so, also, there is something to be known akarmanah, about inaction, about sitting ietly. (The words 'there is' are to be supplied in all the three cases.) Because gatih, the true nature, i.e. the essential nature; karmanah, of action-implying karma etc., viz action, prohibited action and inaction; is gahana, inscrutable, hard to understand.
'What, again, is the essential nature of action etc. which has to be understood, and about which it was promised, "I shall tell you৷৷." (16)?' This is being stated: