In plain words
No one can remain even for a moment without acting; everyone is helplessly driven to action by the guṇas born of Prakṛti.
Word for word
For no one ever remains even a moment not doing action; for everyone, helpless, is made to do action by the guṇas born of prakṛti.
न हि कश्चित् क्षणमपि जातु तिष्ठत्यकर्मकृत्कार्यते ह्यवशः कर्म सर्वः प्रकृतिजैर्गुणैः
Other commentaries
The commentators
▸Bhagavadgītābhāṣyam
कस्मात् पुनः कारणात् कर्मसंन्यासमात्रादेव केवलात् ज्ञानरहितात् सिद्धिं नैष्कर्म्यलक्षणां पुरुषो नाधिगच्छति इति हेत्वाकाङ्क्षायामाह —
न हि यस्मात् क्षणमपि कालं जातु कदाचित् कश्चित् तिष्ठति अकर्मकृत् सन् । कस्मात् ? कार्यते प्रवर्त्यते हि यस्मात् अवश एव अस्वतन्त्र एव कर्म सर्वः प्राणी प्रकृतिजैः प्रकृतितो जातैः सत्त्वरजस्तमोभिः गुणैः । अज्ञ इति वाक्यशेषः, यतो वक्ष्यति ‘गुणैर्यो न विचाल्यते’(भ. गी. १४ । २३) इति । साङ्ख्यानां पृथक्करणात् अज्ञानामेव हि कर्मयोगः, न ज्ञानिनाम् । ज्ञानिनां तु गुणैरचाल्यमानानां स्वतश्चलनाभावात् कर्मयोगो नोपपद्यते । तथा च व्याख्यातम् ‘वेदाविनाशिनम्’(भ. गी. २ । २१) इत्यत्र ॥ ५ ॥
In plain words
But why exactly does bare renunciation, without knowledge, fail to bring a person to that accomplishment marked by actionlessness? Sensing that the reader wants to know why, Kṛṣṇa now gives the reason himself —
No one, in fact, ever stays still even for a moment without doing something. Why not? Because every living being is helplessly, unfreely, driven into action by the guṇas that arise from its own nature — sattva, rajas, and tamas. 'The ignorant' is the word this verse leaves unsaid but clearly means, and we know that because Kṛṣṇa will later say, 'the one who is not shaken by the guṇas' (BG 14.23) — meaning, implicitly, that someone is shaken by them, and someone is not. Because scripture treats the Sāṅkhyas as a separate class of their own, karma-yoga really belongs only to the ignorant, not to those who already know. For the knowers, untouched by the guṇas as they are, karma-yoga simply has nothing to attach to — there is no movement left in them of their own that it could direct. This was already made clear earlier, at the words 'who knows the Self as imperishable' (BG 2.21).
Close to the Sanskrit
But for what reason does a person not attain the accomplishment characterized by actionlessness from mere renunciation of action alone, devoid of knowledge? Anticipating [the reader's] desire for the reason, [Kṛṣṇa] speaks —
For indeed, because no one at all ever remains, even for a moment's time, without doing action. Why? Because every living being is made to act, is impelled to act, indeed helplessly, indeed without independence, [into] action, by the guṇas born of nature — [i.e.] born from [one's own] nature — sattva, rajas, and tamas. 'The ignorant one' [is] the implied remainder of the sentence, because he will say [later], 'he who is not moved by the guṇas' (BG 14.23) — thus. Because of the [scriptural] separating-out of the Sāṅkhyas, karma-yoga [belongs] indeed only to the ignorant, not to the knowers. But for the knowers, who are not moved by the guṇas, karma-yoga does not apply, because of the absence of any movement [in them] arising from themselves. And thus it has been explained at 'he who knows [the Self as] imperishable' (BG 2.21).