Bhagavad Gita Chapter 4 Verse 17
भगवद् गीता अध्याय 4 श्लोक 17

कर्मणो ह्यपि बोद्धव्यं बोद्धव्यं च विकर्मणः।
अकर्मणश्च बोद्धव्यं गहना कर्मणो गतिः।।4.17।।



English Translation - Swami Sivananda
4.17 For verily (the true nature) of action (enjoined by the scriptures) should be known, also (that) 
of forbidden (or unlawful) action, and of inaction; hard to understand is the nature (path) of action.


English Translation of Sanskrit Commentary By Sri Shankaracharya's
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:


Transliteration Bhagavad Gita 4.17Karmano hyapi boddhavyam boddhavyam cha vikarmanah;
Akarmanashcha boddhavyam gahanaa karmano gatih.


Word Meanings Bhagavad Gita 4.17karmaṇaḥ—recommended action; hi—certainly; api—also; boddhavyam—should be known; boddhavyam—must understand; cha—and; vikarmaṇaḥ—forbidden action; akarmaṇaḥ—inaction; cha—and; boddhavyam—must understand; gahanā—profound; karmaṇaḥ—of action; gatiḥ—the true path