Bhashya
तद्धैतत् आत्मज्ञानं सोपकरणम् 'ओमित्येतदक्षरम्'इत्याद्यैः सहोपासनैः तद्वाचकेन ग्रन्थेन अष्टाध्यायीलक्षणेनसह ब्रह्मा हिरण्यगर्भः परमेश्वरो वा तद्द्वारेण प्रजापतयेकश्यपाय उवाच ; असावपि मनवे स्वपुत्राय ; मनुः प्रजा-भ्यः इत्येवं श्रुत्यर्थसंप्रदायपरम्परयागतम् उपनिषद्विज्ञानम्अद्यापि विद्वत्सु अवगम्यते ।यथेह षष्ठाद्यध्यायत्रये प्रका-शिता आत्मविद्या सफला अवगम्यते, तथा कर्मणां न क-पीडा स्यादित्यत आह-अन्यत्र तीर्थेभ्यः ।तीर्थं नाम शा-स्रानुज्ञाविषयः, ततोऽन्यत्रेत्यर्थः ।सर्वाश्रमिणां च एतत्समा-नम् ।तीर्थेभ्योऽन्यत्र अहिंसैवेत्यन्ये वर्णयन्ति ।कुटुम्बे एवै-तत्सर्वं कुर्वन् , स खल्वधिकृतः, यावदायुषं यावज्जीवम् एवंयथोक्तेन प्रकारेणैव वर्तयन् ब्रह्मलोकमभिसंपद्यते देहान्ते ।न च पुनरावर्तते शरीरग्रहणाय, पुनरावृत्तेः प्राप्तायाः प्रति-षेधात् ।अर्चिरादिना मार्गेण कार्यब्रह्मलोकमभिसंपद्य याव-द्ब्रह्मलोकस्थितिः तावत्तत्रैव तिष्ठति प्राक्ततो नावर्तत इत्यर्थः ।द्विरभ्यासः उपनिषद्विद्यापरिसमाप्त्यर्थः ॥
In plain words
This knowledge of the Self, together with its auxiliary meditations beginning with the syllable 'Om', was transmitted down the sacred lineage: from the Creator to Kasyapa, from Kasyapa to Manu, and from Manu to humanity. Thus this unbroken stream of Upanishadic wisdom is still realized today among the wise. Just as the Self-knowledge taught in the triad of chapters beginning with the sixth is seen to bear fruit, so that one might not doubt any contradiction with ritual duties, the scripture declares: 'elsewhere than in sanctioned paths.' Others interpret this to mean that non-injury is the rule across all orders of life. Performing all these duties right within the household, a qualified person lives out his life according to the prescribed path and attains the world of Brahma upon the dropping of the body. He does not return to take another physical form, for scripture forbids such return. Having reached that realm through the path of light, he abides there for the entire duration of that cosmic world, not returning before its close. The final repetition marks the complete conclusion of the Upanishad's teaching.
Close to the Sanskrit
This knowledge of the Self, along with its accessories such as the meditation starting with 'Om' and the text characterized by the eight chapters, was spoken by Brahma, Hiranyagarbha, or the Supreme Lord through that channel to Prajapati Kasyapa; he too to his son Manu; Manu to his subjects—thus this knowledge of the Upanishad, arrived through the traditional succession of the meaning of scripture, is understood even today among the wise. Just as here in the triad of chapters beginning with the sixth, the illuminated knowledge of the Self is understood to be fruitful, so that there might be no obstruction to rituals, hence it says: 'elsewhere than sacred places.' A 'tīrtha' is named as a subject of scriptural permission; the meaning is elsewhere than that. And for all orders of life this is equal. Others explain: 'elsewhere than sacred places, it is simply non-injury.' Performing all this very thing within the household, he indeed is eligible; living thus throughout his life, as long as he lives, by the stated method, he attains the world of Brahma at the end of his body. And he does not return again for the purpose of taking a body, due to the prohibition of return. Having attained the world of the effected Brahma by the path beginning with light, he stays right there as long as the duration of the world of Brahma; before that he does not return—such is the meaning. The repetition is for the purpose of indicating the completion of the Upanishadic wisdom.