Bhashya
न च निरवयवस्य परमात्मनः असंसारिणः संसार्येकदेशकल्पना न्याय्या, स्वतोऽदेशत्वात् परमात्मनः ।अदेशस्य परस्य एकदेशसंसारित्वकल्पनायां पर एव संसारीति कल्पितं भवेत् ।अथ परोपाधिकृत एकदेशः परस्य, घटकरकाद्याकाशवत् ।न तदा तत्र विवेकिनां परमात्मैकदेशः पृथक्संव्यवहारभागिति बुद्धिरुत्पद्यते ।अविवेकिनां विवेकिनां च उपचरिता बुद्धिर्दृष्टेति चेत्, न, अविवेकिनां मिथ्याबुद्धित्वात्, विवेकिनां च संव्यवहारमात्रालम्बनार्थत्वात्- यथा कृष्णो रक्तश्च आकाश इति विवेकिनामपि कदाचित् कृष्णता रक्तता च आकाशस्य संव्यवहारमात्रालम्बनार्थत्वं प्रतिपद्यत इति, न परमार्थतः कृष्णो रक्तो वा आकाशो भवितुमर्हति ।अतो न पण्डितैर्ब्रह्मस्वरूपप्रतिपत्तिविषये ब्रह्मणः अंशांशेकदेशैकदेशिविकारविकारित्वकल्पना कार्या, सर्वकल्पनापनयनार्थसारपरत्वात् सर्वोपनिषदाम् ।अतो हित्वा सर्वकल्पनाम् आकाशस्येव * निर्विशेषता प्रतिपत्तव्या- 'आकाशवत्सर्वगतश्च नित्यः'‘न लिप्यते लोकदुःखेन बाह्यः’ इत्यादिश्रुतिशतेभ्यः ।न आत्मानं ब्रह्मविलक्षणं कल्पयेत्- उष्णत्मक इवाग्नौ शीतैकदेशम्, प्रकाशात्मके वा सवितरि तमएकदेशम्- सर्वकल्पनापनयनार्थसारपरत्वात् सर्वोपनिषदाम् ।तस्मात् नामरूपोपाधिनिमित्ता एव आत्मनि असंसारधर्मिणि सर्वे व्यवहाराः- ‘रूपं रूपं प्रतिरूपो बभूव’ ‘सर्वाणि रूपाणि विचित्य धीरो नामानि कृत्वाभिवदन् यदास्ते’ इत्येवमादिमन्त्रवर्णेभ्यः- न स्वतः आत्मनः संसारित्वम्, अलक्तकाद्युपाधिसंयोगजनितरक्तस्फटिकादिबुद्धिवत् भ्रान्तमेव न परमार्थतः ।‘ध्यायतीव लेलायतीव’ ‘न कर्मणा वर्धते नो कनीयान्’ ‘न कर्मणा लिप्यते पापकने’ ‘समं सर्वेषु भूतेषु तिष्ठन्तम्’ ‘शुनि चैव श्वपाके च’ इत्यादिश्रुतिस्मृतिन्यायेभ्यः परमात्मनोऽसंसारितैव ।अतः एकदेशो विकारः शक्तिर्वा विज्ञानात्मा अन्यो वेति विकल्पयितुं निरवयवत्वाभ्युपगमे विशेषतो न शक्यते ।अंशादिश्रुतिस्मृतिवादाश्च एकत्वार्थाः, न तु भेदप्रतिपादकाः, विवक्षितार्थैकवाक्ययोगात्- इत्यवोचाम ॥
In plain words
You cannot picture a transmigrating piece inside the Supreme Self, which has no parts and does not transmigrate — because the Supreme, by its very nature, takes up no space at all. Imagine a 'part' of something spaceless doing the transmigrating, and you've simply made the whole Supreme into the transmigrator — there's no way around it. Or say the 'part' comes from some limiting condition, the way a pot or a jar seems to carve out its own little piece of space. Even then, no one who actually sees clearly ever mistakes that pocket of space for a truly separate thing. 'But don't both the confused and the clear-sighted talk this way?' Yes — but for the confused it's simply a mistake, and for the clear-sighted it's only a convenience of speech. Just like when we say the sky is black, or red: even wise people say it, for the sake of getting by in conversation — but the sky was never actually black or red. So the wise never let themselves picture Brahman as a whole with pieces, a thing with fragments, something that changes and something changed — because stripping away exactly that kind of picture is the whole point of every Upanishad. Let go of every such construction, and understand: Brahman has no more distinguishing marks than space does — 'all-pervading and eternal, like space,' 'standing outside, untouched by the world's pain,' say hundreds of scriptures. Don't imagine the Self differs from Brahman the way a cold patch might sit inside fire, whose very nature is heat, or a dark patch inside the sun, whose very nature is light — because, again, every Upanishad exists only to clear such pictures away. So every distinction we make about the Self — which by nature never changes at all — comes only from the labels of name and form we hang on it. 'It took on form after form, matching each one,' 'the wise one names all the shapes he sees, and rests, simply speaking them,' say the ancient verses. Transmigration was never the Self's own nature; it's a trick of the eye, like a clear crystal that looks red because a piece of dyed cloth sits beside it — not real, just seeming. 'It seems to think, seems to waver'; 'it grows no bigger by what it does, no smaller either'; 'no wrongdoing ever stains it'; 'it stands the same in every creature'; 'the same in a dog as in the lowest outcaste' — and from all of this, one thing is settled: the Supreme Self simply does not transmigrate. So once you accept that it has no parts, you cannot seriously entertain a part of it, a change in it, a power belonging to it, or the individual self as something else again. When scripture speaks of a 'portion' of Brahman becoming the self, it is teaching you oneness — not handing you real division. Read alongside what the text actually means, it can only be saying one thing. That is what we have said.
Close to the Sanskrit
And it is not reasonable to imagine a transmigrating part in the partless, non-transmigrating Supreme Self, because the Supreme Self is by its own nature without location. If one imagines a part of the locationless Supreme to be a transmigrator, it would amount to imagining that the Supreme itself is the transmigrator. Or [if one says] the part of the Supreme is made by an adjunct of the Supreme, like space delimited by a pot or jar — then, in that case, no cognition arises in discerning people that a part of the Supreme Self is the subject of separate practical dealing. If [you say]: 'A figurative cognition is observed in both the non-discerning and the discerning' — no; because for the non-discerning it is simply a false cognition, and for the discerning it serves only as a support for mere practical dealing — just as, when it is said 'the sky is black' or 'red', even discerning people sometimes accept the blackness or redness of the sky only for the sake of practical dealing, but the sky cannot in ultimate reality be black or red. Therefore the wise should not, in the matter of understanding Brahman's true nature, entertain the notion of Brahman as portion and portion-holder, part and part-holder, modification and subject of modification — because the whole essence of all the Upanishads is devoted to the removal of every such imagining. Therefore, having abandoned all such imagining, one should understand freedom from distinguishing attributes, just like that of space — 'and, like space, all-pervading and eternal,' 'being external, it is not tainted by the suffering of the world' — from hundreds of such scriptural statements. One should not imagine the Self to be different in character from Brahman — like [imagining] a portion of cold in fire, whose nature is heat, or a portion of darkness in the sun, whose nature is light — because the whole essence of all the Upanishads is devoted to the removal of every such imagining. Therefore, all practical distinctions in the Self, which by nature does not transmigrate, are caused only by the adjuncts of name and form — 'he became conformed to every form, form after form,' 'the wise one, having differentiated all forms and given them names, sits speaking them' — from these and other such Vedic passages. The state of transmigrating does not belong to the Self by its own nature; it is merely an illusion, like the notion of a red crystal produced by conjunction with an adjunct such as lac-dye — not something real in the ultimate sense. 'It seems to meditate, it seems to waver,' 'it does not grow by action, nor become lesser,' 'it is not tainted by evil action,' 'abiding equally in all beings,' 'in a dog, and even in an outcaste' — from these and other reasonings of scripture and tradition, the Supreme Self's very freedom from transmigration [is established]. Therefore, once partlessness is accepted, it is not at all possible to conceive of a part, a modification, a power, or the individual cognizing self, or anything else [as literally being a portion of it]. And the scriptural and traditional statements about 'a portion' and the like serve the purpose of oneness; they do not establish real difference — because they must form a single coherent statement with the intended meaning. Thus we have said.