Bhashya
‘सोऽयास्य आङ्गिरसः’ इत्यादि यथोपन्यस्तमेवोपादीयते उत्तरार्थम् ।‘प्राणो वा अङ्गानां रसः’ इत्येवमन्तं वाक्यं यथाव्याख्यातार्थमेव पुनः स्मारयति ।कथम् ?— प्राणो वा अङ्गानां रस इति ।प्राणो हि ; हि-शब्दः प्रसिद्धौ ; अङ्गानां रसः ; प्रसिद्धमेतत्प्राणस्याङ्गरसत्वं न वागादीनाम् ; तस्माद्युक्तम् ‘प्राणो वा’ इति स्मरणम् ।कथं पुनः प्रसिद्धत्वमित्यत आह— तस्माच्छब्द उपसंहारार्थ उपरित्त्वेन संबध्यते ; यस्माद्यतोऽवयवात्, कस्मादनुक्तविशेषात् ; यस्मात्कस्मात् यतः कुतश्चिच्च, अङ्गाच्छरीरावयवादविशेषितात्, प्राणः उत्क्रामत्यपसर्पति, तदेव तत्रैव, तदङ्गं शुष्यति नीरसं भवति शोषमुपैति ।तस्मादेष हि वा अङ्गानां रस इत्युपसंहारः ।अतः कार्यकारणानामात्मा प्राण इत्येतत्सिद्धम् ।आत्मापाये हि शोषो मरणं स्यात् ।तस्मात्तेन जीवन्ति प्राणिनः सर्वे ।तस्मादपास्य वागादीन्प्राण एवोपास्य इति समुदायार्थः ॥
In plain words
The text begins with 'Āyāsya Āṅgirasa,' taking up the teaching exactly as it was presented to serve the following discussion. The sentence ending with 'Prāṇa is indeed the essence of the limbs' is recalled in its established sense. How so? Prāṇa is the essence; the word 'indeed' points to something universally recognized. It is well-known that Prāṇa is the inner sap of the body's parts, unlike speech and the other organs. Therefore, remembering it as 'Prāṇa indeed' is entirely fitting. How is this well-known? The text explains: the word 'therefore' serves as a summary pointing upwards. From whatever bodily limb—from any part whatsoever—Prāṇa departs, right there that very limb withers, loses its moisture, and dries up. Therefore, Prāṇa is indeed the essence of the limbs: this is the conclusion. Thus, it is established that Prāṇa is the Self underlying all cause and effect. When this Self departs, withering and death follow; by it alone all living creatures draw their breath. Therefore, leaving aside speech and the other limited organs, Prāṇa alone is to be meditated upon—this is the final purport of the whole.
Close to the Sanskrit
This 'Āyāsya Āṅgirasa' and so forth is taken up just as presented for the sake of the subsequent matter. The sentence ending with 'Prāṇa indeed is the essence of the limbs' is recalled with its already explained meaning. How? Prāṇa indeed; the word 'hi' is in the sense of notoriety; is the essence of the limbs; this being-the-essence-of-the-limbs of Prāṇa is well-known, not of speech and others; therefore the remembrance 'Prāṇa indeed' is appropriate. How again is it well-known? Regarding this he says— the word 'tasmāt' is connected as a summarizing term upwards; from whatever limb, from whatever unspecified part, from whichever limb whatsoever of the body, unspecialized, Prāṇa steps out, moves away, right there that very limb dries up, becomes devoid of sap, attains dryness. Therefore this one indeed is the essence of the limbs—this is the conclusion. Hence it is established that Prāṇa is the Self of cause and effect. For upon the departure of the Self there would be desiccation and death. Therefore all living beings live by it. Therefore, casting aside speech and others, Prāṇa alone is to be meditated upon—this is the collective meaning.