B.G 4.17

कर्मणोह्यपि बोद्धव्यं बोद्धव्यं च विकर्मणः। अकर्मणश्च बोद्धव्यं गहना कर्मणो गतिः ॥१७॥

karmaṇohyapi boddhavyaṁ boddhavyaṁ ca vikarmaṇaḥ। akarmaṇaśca boddhavyaṁ gahanā karmaṇo gatiḥ ॥17॥

[कर्मणः हि अपि बोद्धव्यं बोद्धव्यं च विकर्मणः। अकर्मणः च बोद्धव्यं गहना कर्मणो गतिः॥
karmaṇaḥ = from action; hi = indeed; api = also; boddhavyaṁ = insight should be understood; boddhavyaṁ = insight should be understood; ca = and; vikarmaṇaḥ = from prohibited action;। akarmaṇaḥ = non-performance of action; ca = and; boddhavyaṁ = insight should be understood; gahanā = profound and deep; karmaṇo = of action; gatiḥ = course;॥]

One needs to grasp the understanding of right action, prohibited actions insight must be grasped, indeed, one needs to grasp the understanding of non-performance actions. The ways of action are truly profound.

Gīta Bhāshya 4.17

'Vikarma' differs from right-action ('karma') and non-action ('akarma'). 'Vikarma' means prohibited action. It is further binding. Gaining insight into ways of karma is crucial for discriminating between them. It is a prerequisite to perceive the lord directly, and to get liberated.

न केवलं तत् ज्ञात्वा मोक्ष्यसे, ज्ञात्वैव इत्याशयवानाह - कर्मण इति। तच्चोक्तम्–

na kevalaṁ tat jñātvā mokṣyase, jñātvaiva ityāśayavānāha - karmaṇa iti। taccoktam–

[na = not; kevalaṁ = merely; tat = that; jñātvā = knowing; mokṣyase = you will be liberated; jñātvaiva = having known, indeed; ityāśayavānāha = also having the insight, it is said; karmaṇa = "karmaṇa", i.e. regarding action; iti = thus;। taccoktam = therefore, it is said:]

Just by merely knowing (about the action to be performed) one does not get liberated. Having known, one must also gain insight 'regarding action' is indicated by the verse 'karmaṇa'.

"अज्ञात्वा भगवान् कस्य कर्माकर्मविकर्मकम्। दर्शनं याति हि मुने कुतो मुक्तिश्च तद् विना॥"

इति।

"ajñātvā bhagavān kasya karmākarmavikarmakam। darśanaṁ yāti hi mune kuto muktiśca tad vinā॥"

iti।

[ajñātvā = without knowing; bhagavān = the lord; kasya = whose; karmākarmavikarmakam = right action, non-action and prohibited action;। darśanaṁ = direct perception; yāti = one attains; hi = indeed; mune = O sage; kuto = from where; muktiśca = liberation, and; tad = that; vinā = without;॥]

[iti। = thus states testimonal;]

O Sage, without gaining insight into the right action, non-action, and prohibited action, How is it possible to gain the direct perception of the lord, and without it how liberation is possible?

-states the testimonial.

अकर्म कर्माकरणम्। कर्माकर्मान्यत् विकर्म निषिद्धम्। बन्धकत्वात्। ततो विविच्य कर्मादि बोद्धव्यम् इत्यादि। न च शापादिना।

akarma karmākaraṇam। karmākarmānyat vikarma niṣiddham। bandhakatvāt। tato vivicya karmādi boddhavyam ityādi। na ca śāpādinā।

[akarma = 'akarma' means'; karmākaraṇam = action, not, doing;। karmākarmānyat = different from right action and non-action; vikarma = is 'vikarma'; niṣiddham = which means prohibited action;। bandhakatvāt = due to being binding;। tato = therefore; vivicya = discriminate; karmādi = different kinds of actions; boddhavyam = by gaining insight; ityādi = and so on;। na ca = not regarding; śāpādinā = curse etc.]

'akarma' means non-performance of action. Different from right-action and non-action is 'vikarma', which means prohibited action, as it is further binding. Therefore, discriminate different actions by 'gaining insight' is the intended meaning. It is not about a curse etc. (as explained by other commentaries.)

"कवयोऽप्यत्र मोहिताः।"

"kavayo'pyatra mohitāḥ।"

[kavayo'pyatra = even the wise in this context; mohitāḥ = are deluded;]

"Even the wise are deluded in these situations."

अशक्यं चैतत् ज्ञातुम् इत्याह - गहनेति ॥१७॥

aśakyaṁ caitat jñātum ityāha - gahaneti ॥17॥

[aśakyaṁ = impossible; caitat = and, this; jñātum = to know; ityāha = thus it is indicated; - gahaneti = by using the word 'gahana' which means "profound and deep"]

-such expression shows it is almost impossible to know (i.e. gain insight into workings of the actions). Same is indicated by the word 'gahana' which means it is "profound and deep".