(त्र्यन्नब्राह्मणं वा अविद्याविषयसंसारतत्त्वप्रदर्शकं ब्राह्मणं वा उपसंहारब्राह्मणम्) त्रयं वा इदं नाम रूपं कर्म ।तेषां नाम्नां वागित्येतदेषामुक्थम् ।अतो हि सर्वाणि नामान्युत्तिष्ठन्ति ।एतदेषां साम ।एतद्धि सर्वैर्नामभिः समम् ।एतदेषां ब्रह्म ।एतद्धि सर्वाणि नामानि बिभर्ति ॥१,६.१ ॥
In plain words
This is threefold: name, form and work. Of names, speech is the Uktha, for from it all names arise. It is their Sāman, for it is the same as all names. It is their Brahman, for it bears all names.
The commentators
Bṛhadāraṇyakopaniṣadbhāṣyam· Leaf 8.228· bhāṣya
यदेतदविद्याविषयत्वेन प्रस्तुतं साध्यसाधनलक्षणं व्याकृतं जगत् प्राणात्मप्राप्यन्तोत्कर्षवदपि फलम् , या चैतस्य व्याकरणात्प्रागवस्था अव्याकृतशब्दवाच्या-वृक्षबीजवत् सर्वमेतत् त्रयम् ; किं तन्त्रयमित्युच्यते-नाम रूपं कर्म चेति अनात्मैव- न आत्मा यत्साक्षादपरोक्षाद्ब्रह्म ; तस्मादस्माद्विरज्येतेत्येवमर्थः त्रयं वा इत्याद्यारम्भः । न ह्यस्मात् अनात्मनः अव्यावृत्तचित्तस्य आत्मानमेव लोकम् अहं ब्रह्मास्मीत्युपासितुं बुद्धिः प्रवर्तते, बाह्यप्रत्यगात्मप्रवृत्त्योर्विरोधात् । तथा च काठके-‘पराञ्चि खानि व्यतृणत्स्वयम्भूस्तस्मात्पराङ्पश्यति नान्तरात्मन् । कश्चिद्धीरः प्रत्यगात्मानमैक्षदावृत्तचक्षुरमृतत्वमिच्छन्’ इत्यादि ॥
In plain words
The differentiated universe of means and ends—the entire realm born of ignorance, complete with rewards as exalted as the cosmic breath—together with its seed-state prior to manifestation called the unmanifest, this entire triad of name, form, and action is purely the non-self. It is not the immediate, direct Brahman. Therefore, the text begins with 'This indeed is a triad...' precisely to create detachment from it. For the mind of one who is not detached from this non-self cannot turn toward meditating 'I am Brahman,' because outward-looking and inward-looking tendencies directly oppose one another. As the Katha Upanishad says: 'The self-existent Creator pierced the senses outward, so man looks outward, not into the inner self. A rare wise man, seeking immortality, turns his gaze inward and beholds the inner Self.'
Close to the Sanskrit
That which has been presented as the domain of nescience—the differentiated universe characterized by means and ends, and possessing fruits up to the state of prana—and that causal state prior to manifestation which is designated by the word 'unmanifest', like a seed of a tree, all this triad (name, form, and action) is indeed non-self, not the Self which is directly and immediately Brahman; therefore, the purpose of commencing with 'This indeed is a triad...' is that one should feel dispassionate towards this. For the intellect of one whose mind is not detached from this non-self does not proceed to meditate upon the Self as 'I am Brahman', because of the contradiction between the extroverted and introverted tendencies. And thus in the Katha Upanishad: 'The self-existent one pierced the apertures outward; therefore one looks outward, not within the inner self. A certain wise person, desiring immortality, saw the inner Self with averted eyes,' and so forth.
Bṛhadāraṇyakopaniṣadbhāṣyam· Leaf 8.230· bhāṣya
तत्प्रतिपादयति-एतत् शब्दसामान्यं हि यस्मात् शब्दविशे- षान् सर्वाणि नामानि बिभर्ति धारयति स्वरूपप्रदानेन । एवं कार्यकारणत्वोपपत्तेः सामान्यविशेषोपपत्तेः आत्मप्रदा- नोपपत्तेश्च नामविशेषाणां शब्दमात्रता सिद्धा । एवमुत्तर- योरपि सर्वं योज्यं यथोक्तम् ॥
In plain words
This is established: generic sound sustains all specific names by providing their very essence. Thus, because the relation of cause and effect, general and particular, and the bestowal of identity are all established, specific names are proven to be mere words. The same reasoning is to be applied to the remaining two [form and action] as already explained.
Close to the Sanskrit
That is established: because this generic sound sustains all particular names by bestowing their essential nature. Thus, through the establishment of the cause-effect relation, the relation of general and particular, and the granting of reality, the status of particular names as mere words is proven. Similarly, all should be applied to the remaining two as stated.