Bhashya
तत्र चतुष्टयविशेषणविशिष्टं मूर्तम्, तथा अमूर्तं च; तत्र कानि मूर्तविशेषणानि कानि चेतराणीति विभज्यते ।तदे-तन्मूर्तं मूर्च्छितावयवम् इतरेतरानुप्रविष्टायववं घनं संहतमित्यर्थः ।किं तत् ? यदन्यत्; कस्मादन्यत् ? वायोश्चान्तरिक्षाच्च भूतद्वयात्- परिशेषात्पृथिव्यादिभूतत्रयम् ; एतन्मर्त्यम्- यदेतन्मूर्ताख्यं भूतत्रयम् इदं मर्त्यं मरणधर्मि; कस्मात् ? यस्मात्स्थितमेतत्; परिच्छिन्नं ह्यर्थान्तरेण संप्रयुज्यमानं विरुध्यते-यथा घटः स्तम्भकुड्यादिना; तथा मूर्तं स्थितं परिच्छिन्नम् अर्थान्तरसंबन्धि ततोऽर्थान्तरविरोधान्मर्त्यम्; एतत्सत् विशेष्यमाणासाधारणधर्मवत्, तस्माद्धि परिच्छिन्नम्, परिच्छिन्नत्वान्मर्त्यम्, अतो मूर्तम्; मूर्तत्वाद्वा मर्त्यम्, मर्त्यत्वात्स्थितम्, स्थितत्वात्सत् ।अतः अन्योन्याव्यभिचारात् चतुर्णां धर्माणं यथेष्टं विशेषणविशेष्यभावो हेतुहेतुमद्भावश्च दर्शयितव्यः ।सर्वथापि तु भूतत्रयं चतुष्टयविशेषणविशिष्टं मूर्तं रूपं ब्रह्मणः ।तत्र चतुर्णामेकस्मिन्गृहीते विशेषणे इतरद्गृहीतमेव विशेषणमित्याह- तस्यैतस्य मूर्तस्य, एतस्य मर्त्यस्य, एतस्य स्थितस्य, एतस्य सतः- चतुष्टयविशेषणस्य भूतत्रयस्येत्यर्थः- एष रसः सार इत्यर्थः; त्रयाणां हि भूतानां सारिष्ठः सविता; एतत्साराणि त्रीणि भूतानि, यत एतत्कृतविभज्यमानरूपविशेषणानि भवन्ति; आधिदैविकस्य कार्यस्यै-तद्रूपम्- यत्सविता यदेतन्मण्डलं तपति; सतो भूतत्रयस्य हि यस्मात् एष 'रस इति एतद्गृह्यते; मूर्तो ह्येष सविता तपति, सारिष्ठश्च ।यत्तु आधिदैविकं करणं मण्डलस्याभ्यन्तरम्, तद्वक्ष्यामः ॥
In plain words
The formed carries four marks, and so does the formless in its own way; here we sort out which marks belong to which. 'This is the formed' simply means: its parts have congealed, fused into one another, so it's dense and solid. What counts as 'the formed'? Whatever isn't wind or space — which, by elimination, leaves the other three elements: earth and its companions. 'This is mortal' means: this trio called 'formed' is bound to die. And why? Because it's fixed. Anything limited runs into other things and gets stopped by them — the way a pot bumps against a pillar or a wall. The formed, being fixed, is limited in just that way, capable of colliding with something else; and it's exactly that collision with other things that makes it mortal. 'This is sat' means it carries some distinguishing mark that sets it apart from everything else. And really, each of these implies the others: because it's limited, it's mortal; because it's mortal, it's formed — or, read the other way, because it's formed, it's mortal; because it's mortal, it's fixed; because it's fixed, it's sat. They all imply one another, so you can lay out the four properties as cause leading to effect in whichever order suits you. Either way, this trio of elements, wearing all four marks, is Brahman's formed side. And notice: grab hold of any one of the four, and you already have the other three — which is why he puts it this way: 'of this formed, this mortal, this fixed, this sat thing — this is its essence, its core.' Of the three elements, the sun is the finest essence; they take their essence from it, because it's the sun's own action that gives each of them its distinct shape. This — the sun, this blazing disc — is exactly the visible form the deity-side effect takes. It earns the name 'essence' of the three real elements precisely because this formed, burning sun is both their finest part and the source of their shape. As for the hidden power behind that disc, the deity itself — we'll get to that later.
Close to the Sanskrit
There, the formed is characterized by four qualifying attributes, and likewise the formless too; there, it is being analyzed which are the attributes of the formed and which are the other ones. 'This is the formed' means: whose parts are congealed, whose parts have mutually interpenetrated one another, dense, compact — that is the meaning. What is that? 'That which is other'; other than what? Than the pair of elements, wind and space — by elimination, the trio of elements beginning with earth. 'This is mortal' means: this trio of elements called 'formed' — this is mortal, subject to the property of dying; why? because this is fixed; for something limited, when brought into conjunction with another thing, meets obstruction — as a pot is obstructed by a pillar, a wall, and the like; likewise the formed, being fixed, is limited, capable of relation with another thing; therefore, because of this obstruction by another thing, it is mortal. 'This is sat' means: possessing an uncommon property by which it is distinguished. For from that, indeed, it is limited; because of being limited, it is mortal; hence it is formed; or, because of being formed, it is mortal; because of being mortal, it is fixed; because of being fixed, it is sat. Therefore, because of their mutual invariable concomitance, among the four properties, the relation of qualifier and qualified and the relation of cause and effect are to be shown as one wishes. In any case, however, the trio of elements, characterized by the four attributes, is the formed form of Brahman. There, when one of the four attributes is taken, the other is understood as taken too — this he states: 'of that, this formed, this mortal, this fixed, this sat' — meaning the trio of elements characterized by the four attributes — 'this is the essence' meaning the essential core — that is the meaning; for, of the three elements, the sun is the most essential. These three elements have this as their essence, since it is by this that their distinguishing forms come to be differentiated. This is the form of the deity-related effect — namely the sun, this orb, which burns. For, since this is understood as the 'essence' of the trio of elements that are sat, since this sun, being itself formed, burns, and is the finest essence. But as for the deity-related power that is within the orb, that we shall explain later.