गच्छन्त्यपुनरावृत्तिं ज्ञाननिर्धूतकल्मषाः ॥ १७ ॥ (5.17)
With the intellect set on that very Self as their goal and devoted to That the sages with their sins routed by Knowledge, get to That from where there is no return.
तद्बुद्ध्या: are those who as a result of the full perfection of their disciplines through renunciation of all external objects have their intellect (बुद्दि), the mental modification in the form of direct experience, merged in that very Reality which is the supreme Self, which is Existence-Knowledge-Bliss (सत्यं-ज्ञानं-अनन्तं) through and through and is revealed by knowledge; i.e. those who are ever absorbed in the निर्बिज (seedless, objectless) Self absorption (vide Patanjali Yoga Sutra 1.50 – तद्वैराग्यादपि दोषवीजक्षये कैवल्यम्॥५०॥) .
Then, is it that there are jivas, who are the knowers, and the Reality which is Brahman that is to be known, so that there is a difference in the form of a knower and the known?
Krishna says, no, they are तदात्मान:, those whose Self is That, those who have that (तत्) supreme Brahman Itself as their Self (आत्मा).
For, the notion of a knower and the known is a display of Maayaa and it is not opposed to the factual non-difference. This is the idea.
Is not the qualification तदात्मान: useless?
For that alone can be a qualification of an enlightened person which distinguishes him from an unenlightened person.
Since even the ignorant have in reality, That as their Self, therefore how can they be differentiated?
Answer: No, that qualification is meant for denying the enlightened person’s identity with the non-Self.
Since the ignorant have self-identification with non-selves such as body etc. therefore they are mentioned as तदात्मान:.
The enlightened, however, being free from self-identification with body etc are referred to as तदात्मान: .
तदात्मान: is referred here by way of excluding what is opposed to the knowledge of the Self. Thus the qualification is justified.
Well, since so long as the distrations resulting from the performance of actions continue, how can there be cessation of self-identification with body?
As to that Sri Krishna says they are तन्निष्ठा:.
तन्निष्ठा: are those who have their steadfastness (निष्ठा) in that (तत् ) Brahman alone, by excluding all distractions resulting from performing work.
That is, they are immersed in deliberating solely on That by renouncing all actions.
So long as attachment to the fruits of actions continues, how can there be renunciation of the actions which are their means?
With regard to that Sri Krishna says: they are तत्परायणाः.
तत्परायणाः are those to whom That alone is the supreme (पर ) Goal (अयन ) to be reached; that is those who are indifferent to everything.
Here by ‘तद्बुदधा:, those who have their intellect absorbed in That’ is meant direct realization.
By तदात्मान: is meant the maturity of निदिध्यासन, which leads to the cessation of विपरीत-भावना (contrary thought) in the form of self-identity with the non-self.
By तन्निष्ठा: is meant विचार (inquiry) on Vedanta, in the form of perfection of श्रावण (hearing) and मनन (contemplating).
This is preceded by renunciation of all actions and which leads to the removal of असम्भावना (idea of impossibility).
This असम्भावना is with regard to the means and the object of knowledge.
By तत्परायणाः is meant intensity of detachment.
Thus it is to be noted that the later ones are successively the causes of the preceding ones.
Men of renunciation, who have the above mentioned qualities, गच्छन्ति, attain;
अपुनरावृत्तिं. the state of no return i.e. Liberation; consisting in the absense of becoming embodied again.
Why should not those who are liberated once have embodiment again?
As to that Sri Krishna says ज्ञाननिर्धूतकल्मषाः, those whose dirt, action, which is naturally virtuous or vicious and is the cause of reincarnation, has been removed away, eradicated, together with its root, by Knowledge.
The idea is: when as a result of eradication of the beginningless ignorance, by knowledge, its effect, viz. action, becomes dissipated, then how can there be reincarnation which is rooted in that?
So far Sri Krishna explained the result of Knowledge as विदेहकैवल्यप्राप्ति, freedom from re-embodiment after death of this body.
In the next verse He speaks of the result of that Knowledge as जीवन्मुक्ति, Liberation while still alive even as प्रारब्धकर्म persists.