Bhashya
औपनिषदंमन्या अपि केचित्प्रक्रियां रचयन्ति - मूर्ता-मूर्तराशिरेकः, परमात्मराशिरुत्तमः, ताभ्यामन्योऽयं मध्यमःकिल तृतीयः कर्त्रा भोक्त्रा विज्ञानमयेन अजातशत्रुप्रतिबो-धितेन सह विद्याकर्मपूर्वप्रज्ञासमुदायः ; प्रयोक्ता कर्मराशिः,प्रयोज्यः पूर्वोक्तो मूर्तामूर्तभूतराशिः साधनं चेति ।तत्र चतार्किकैः सह संधिं कुर्वन्ति ।लिङ्गाश्रयश्च एष कर्मराशि-रित्युक्त्वा, पुनस्तत्रत्रस्यन्तः सांख्यत्वभयात् - सर्वः कर्मराशिः - पुष्पाश्रय इव गन्धः पुष्पवियोगेऽपि पुटतैलाश्रयोभवति, तद्वत् - लिङ्गवियोगेऽपि परमात्मैकदेशमाश्रयति, सपरमात्मैकदेशः किल अन्यत आगतेन गुणेन कर्मणा स-गुणो भवति निर्गुणोऽपि सन् , स कर्ता भोक्ता बध्यतेमुच्यते च विज्ञानात्मा - इति वैशेषिकचित्तमप्यनुसरन्ति ;स च कर्मराशिः भूतराशेरागन्तुकः, स्वतः निर्गुण एव पर-मात्मैकदेशत्वात् , स्वतः उत्थिता अविद्या अनागन्तुकापिऊषरवत् अनात्मधर्मः - इत्यनया कल्पनया सांख्यचित्तमनु-वर्तन्ते ॥
In plain words
Some people who like to think of themselves as authorities on the Upaniṣads build their own theory. They say there are three masses. One is everything formed and formless — the whole world of shape and shapelessness. Another, the highest, is the Supreme Self. And there's a third, a middle one, they claim — the one who acts and enjoys, the same conscious self that Ajātaśatru woke into awareness: a bundle made of knowledge, action, and the leftover imprint of both. Of this bundle, the karma-part does the using, and the old formed-and-formless mass is what gets used — the tool it works with. Here they try to make peace with the logicians too. Having said this bundle of karma rests on the subtle body, they suddenly get nervous — afraid of sounding just like the Sāṃkhya school — so they add: this whole mass of karma is like fragrance. Fragrance sits in a flower, but once separated from the flower it can still sit in a bottle of scented oil. In the same way, once separated from the subtle body, this karma-mass takes shelter in a fragment of the Supreme Self. That fragment of the Supreme Self, they say, is naturally free of qualities, but picks up qualities from karma that comes in from outside — and that very fragment, now called the cognitive self, becomes the one who acts, enjoys, gets bound, and gets free. With that move they're borrowing from the Vaiśeṣikas too. And this karma-mass, they add, is a stranger to the mass of physical elements — in itself unqualified, being nothing but a piece of the Supreme Self — while ignorance, though it springs up on its own and isn't a stranger the way karma is, still isn't a real property of the Self, any more than barrenness is a real property of soil. With this bit of invention, they end up following the Sāṃkhya line of thinking after all.
Close to the Sanskrit
Some also, who fancy themselves knowers of the Upaniṣads, construct a theory: the mass of the formed-and-formless is one; the mass that is the Supreme Self is the highest; different from both of these is this third, the middle one, indeed — as agent and enjoyer, together with the vijñānamaya awakened by Ajātaśatru — the aggregate of knowledge, action, and prior cognition. The mass of karma is the user; the previously-mentioned mass of formed-and-formless elements is the thing used, and it is the instrument. And there they make a reconciliation with the logicians. Having said that this mass of karma has the subtle body as its support, then, trembling at that point out of fear of Sāṃkhya-hood, they say: the entire mass of karma, just as fragrance, resting on a flower, remains resting in the scented-oil packet even after separation from the flower, likewise, even upon separation from the subtle body, takes refuge in a portion of the Supreme Self. That portion of the Supreme Self, indeed, by a quality — karma — coming from elsewhere, becomes qualified, though qualityless in itself; that same one, as the cognitive self, is the doer, the enjoyer, becomes bound and becomes released — thus they follow the thinking of the Vaiśeṣikas as well. And that mass of karma is adventitious with respect to the mass of elements, being itself qualityless indeed, because it is a portion of the Supreme Self; nescience, though arisen of itself and not adventitious, is nonetheless, like the barrenness of saline soil, not a property of the Self — by this device they conform to Sāṃkhya thinking.