ता वा अस्यैता हिता नाम नाड्यो यथा केशः सहस्रधा भिन्नस्तावताणिम्ना तिष्ठन्ति ।शुक्लस्य नीलस्य पिङ्गलस्य हरितस्य लोहितस्य पूर्णाः ।अथ यत्रैनं घ्नन्तीव जिनन्तीव हस्तीव विच्छाययति गर्तमिव पतति ।यदेव जाग्रद्भयं पश्यति तदत्राविद्यया मन्यते ।अथ यत्र देव इव राजेवाहमेवेदं सर्वोऽस्मीति मन्यते ।सोऽस्य परमो लोकः ॥४,३.२० ॥
In plain words
There are in him those channels called Hitā, as fine as a hair split a thousandfold, filled with white, blue, tawny, green and red. Now when they seem to strike him or to overpower him, when an elephant seems to be tearing at him, when he seems to fall into a pit, then in his ignorance he imagines the very fear he sees while awake. But when he thinks that he is as it were a god, as it were a king, that he is all this — that is his highest world.
The commentators
Bṛhadāraṇyakopaniṣadbhāṣyam· Leaf 9.230
यदि अस्य अयं स्वभावः- सर्वसंसारधर्मशून्यता, परो- पाधिनिमित्तं च अस्य संसारधर्मित्वम्; यन्निमित्तं च अस्य परोपाधिकृतं संसारधर्मित्वम्, सा च अविद्या- तस्या अविद्यायाः किं स्वाभाविकत्वम्, आहोस्वित् कामकर्मादि- वत् आगन्तुकत्वम्; यदि च आगन्तुकत्वम्, ततो विमोक्ष उपपद्यते; तस्याश्च आगन्तुकत्वे का उपपत्तिः, कथं वा न आत्मधर्मः अविद्येति- सर्वानर्थबीजभूताया अविद्यायाः सतत्त्वावधारणार्थं परा कण्डिका आरभ्यते-
ताः वै, अस्य शिरःपाण्यादिलक्षणस्य पुरुषस्य, एताः हिता नाम नाड्यः, यथा केशः सहस्रधा भिन्नः, तावता दुःखस्वरूपत्वात् । किं बहुना, यदेव जाग्रत् भयं पश्यति हस्त्या- दिलक्षणम्, तदेव भयरूपम् अत्र अस्मिन्स्वप्ने विनैव हस्त्यादि- रूपं भयम् अविद्यावासनया मृषैव उद्भूतया मन्यते । अथ पुनः यत्र अविद्या अपकृष्यमाणा विद्या चोत्कृष्यमाणा — किंवि- षया किंलक्षणा चेत्युच्यते- अथ पुनः यत्र यस्मिन्काले, देव इव स्वयं भवति, देवताविषया विद्या यदा उद्भूता जागरि- तकाले, तदा उद्भूतया वासनया देवमिव आत्मानं मन्यते ; स्वप्नेऽपि तदुच्यते- देव इव, राजेव राज्यस्थः अभिषिक्तः, स्वप्नेऽपि राजा अहमिति मन्यते राजवासनावासितः । एवम् अत्यन्तप्रक्षीयमाणा अविद्या उद्भूता च विद्या सर्वा- त्मविषया यदा, तदा स्वप्नेऽपि तद्भावभावितः- अहमेवेदं सर्वोऽस्मीति मन्यते ; स यः सर्वात्मभावः, सोऽस्य आत्मनः परमो लोकः परम आत्मभावः स्वाभाविकः । यत्तु सर्वा- त्मभावादर्वाक् वालाग्रमात्रमपि अन्यत्वेन दृश्यते- नाहम- स्मीति, तदवस्था अविद्या ; तया अविद्यया ये प्रत्युपस्था- पिताः अनात्मभावा लोकाः, ते अपरमाः स्थावरान्ताः ; तान् संव्यवहारविषयान् लोकानपेक्ष्य अयं सर्वात्मभावः समस्तो- ऽनन्तरोऽबाह्यः, सोऽस्य परमो लोकः । तस्मात् अपकृष्य- माणायाम् अविद्यायाम्, विद्यायां च काष्ठां गतायाम्, सर्वात्म- भावो मोक्षः, यथा स्वयंज्योतिष्ट्वं स्वप्ने प्रत्यक्षत उपलभ्यते
In plain words
Suppose this really is the Self's own nature: entirely empty of every property that belongs to a life caught in transmigration, and whatever makes it seem otherwise comes only from some alien conditioning pinned onto it. And the thing responsible for pinning those transmigratory properties onto it — that is nescience, avidyā. So the question has to be put plainly: is this avidyā simply built into the Self, or does it merely arrive, the way desire and action arrive? Because if it merely arrives, freedom becomes possible after all. But what grounds are there for calling it a mere arrival — and, for that matter, why isn't it simply a property of the Self? To settle, once and for all, what this avidyā really is, the seed from which every evil grows, the next section now begins.
These are called his hitā channels — this person shaped like a head, hands, and everything else — fine as a hair split into a thousand strands, and just as fine, just as hard to grasp. What more is there to say: whatever elephant-shaped fear he has ever seen while awake, that very same fear, right here in this dream, with no actual elephant anywhere near him, he simply imagines out of the impression nescience has left behind — nothing but illusion. Now once more: as nescience keeps receding and knowledge keeps growing, what is that knowledge about, and what does it look like? Here is the answer. Once more: there comes a moment when he feels like a god himself — when knowledge of a deity, gathered while awake, has arisen, then, carried by that very impression, he imagines himself to be god-like. The same thing happens in dream: like a god, like a king enthroned and anointed, in dream too he thinks 'I am a king,' soaked through with the impression of kingship. And in just this way, once nescience has nearly worn away completely and knowledge of the Self of everything has arisen, then, even in dream, steeped in that very state, he thinks, 'I alone am all this.' That state of being everything — that is this Self's highest world, its supreme and utterly natural condition. But whatever is seen as other than oneself, even by a hair's breadth, short of that state of being everything — the thought 'I am not that' — that condition is nescience, plain and simple. The worlds of separateness nescience puts in front of him are never the highest; they run all the way down to the merely stationary. Set against those ordinary, everyday worlds, this state of being everything — whole, with nothing inside it and nothing outside it — is his highest world. So once nescience is receding and knowledge has reached its very limit, this state of being everything is liberation — exactly as self-luminosity is directly felt in dream...
Close to the Sanskrit
If this is the Self's own nature — utter emptiness of every property of transmigratory existence — and its having the properties of transmigratory existence is caused by an alien conditioning adjunct; and that by which its having transmigratory properties is brought about by an alien conditioning adjunct is nescience — then, of that nescience, is it natural, or, like desire and action and so on, is it adventitious? And if it is adventitious, then liberation becomes possible. But of its being adventitious, what is the justification, or how is nescience not a property of the Self? — In order to ascertain the true nature of this nescience, which is the seed of every evil, the next section now begins.
These, indeed, are the channels called hitā belonging to this person characterized by head, hands, and so on, as fine as a hair split a thousandfold, being, to that same degree, of the nature of suffering. What need of much talk: whatever fear characterized by an elephant and the like one sees while awake, that same fear-form, here, in this dream, even without any actual elephant-form at all, is imagined as fear that has arisen falsely indeed, through an impression left by nescience. Now again: where nescience is receding and knowledge is increasing — of what object, and of what character, is now stated. Now again: where, at which time, he himself becomes like a god — when knowledge whose object is a deity has arisen in the waking state, then, through the impression that has arisen from that, he imagines himself, the Self, as like a god. In dream too, this is said: like a god, like a king established in the kingdom, anointed; in dream too he thinks 'I am a king,' impregnated with the impression of kingship. Thus, when nescience is being utterly diminished, and knowledge whose object is the Self of all has arisen, then, even in dream, pervaded by that state, he thinks 'I alone am all this.' That which is the state of being all — that is this Self's highest world, the highest state of the Self, its natural state. But that which, short of the state of being all, is seen as other even to the extent of a hair's tip — the thought 'I am not that' — that state is nescience. The worlds of non-Self-hood presented by that nescience are not supreme, ending with the stationary. Measured against those worlds which are the objects of ordinary transaction, this state of being all — entire, without interior, without exterior — is his highest world. Therefore, when nescience is receding and knowledge has reached its culmination, the state of being all is liberation, just as self-luminosity is directly apprehended in dream...
Bṛhadāraṇyakopaniṣadbhāṣyam· Leaf 9.234· bhāṣya
भावे सर्वात्मना निवर्तते, रज्ज्वामिव सर्पज्ञानं रज्जुनिश्चये ; तच्चोक्तम्- 'यत्र त्वस्य सर्वमात्मैवाभूत्तत्केन कं पश्येत्' इत्यादि ; तस्मात् न आत्मधर्मः अविद्या ; न हि स्वाभाविकस्योच्छित्तिः कदाचिदप्युपपद्यते, सवितुरिव औष्ण्यप्रकाशयोः । तस्मात् तस्या मोक्ष उपपद्यते ॥
In plain words
Once that experience of being everything dawns, nescience departs completely — the way the very notion of a snake disappears the instant you become certain it was only ever a rope. And this is exactly what has been said elsewhere: 'But when for him everything has become nothing but the Self, then what could he see, and by what, and whom?' and so on. So nescience is not a property of the Self at all. Because whatever truly belongs to a thing by its own nature can never be destroyed, not at any time — no more than heat and light can ever be taken from the sun. And that is exactly why freedom from it is possible.
Close to the Sanskrit
When that state occurs, it departs altogether, just as the notion of a snake departs with respect to a rope, when certainty about the rope arises. And this has been said: 'But when for him everything has become the very Self, then by what, and whom, would he see?' and so on. Therefore nescience is not a property of the Self. For the destruction of what is natural is never possible at any time whatsoever — as with heat and light in the case of the sun. Therefore its liberation follows.