Bhashya
आत्मा हि नाम सर्वजन्तूनां प्रत्यक्चेतनः स्वसंवेद्यः प्रसिद्धः तेनैव स्वरूपेणोन्नीय अशरीरो व्योमवत्सर्वगत आत्मा ब्रह्मेत्यवगन्तव्यम् ।तच्च आत्मा ब्रह्म अमृतम् अमरणधर्मा ।अतः ऊर्ध्वं मन्त्रः ।प्रजापतिः चतुर्मुखः तस्य सभां वेश्म प्रभुविमितं वेश्म प्रपद्ये गच्छेयम् ।किंच यशोऽहं यशो नाम आत्मा अहं भवामि ब्राह्मणानाम् ।ब्राह्मणा एव हि विशेषतस्तमुपासते ततस्तेषां यशो भवामि ।तथा राज्ञां विशां च ।तेऽप्यधिकृता एवेति तेषामप्यात्मा भवामि ।तद्यशोऽहमनुप्रापत्सि अनुप्राप्तुमिच्छामि ।स ह अहं यशसामात्मनां देहेन्द्रियमनोबुद्धिलक्षणानामात्मा ।किमर्थमहमेवं प्रपद्य इति, उच्यते— श्येतं वर्णतः पक्कबदरसमं रोहितम् ।तथा अदत्कं दन्तरहितमप्यदत्कं भक्षयितृ स्त्रीव्यञ्जनं तत्सेविनां तेजोबलवीर्यविज्ञानधर्माणाम् अपहन्तृ विनाशयित्रियेतत् ।यदेवंलक्षणं श्येतं लिन्दु पिच्छलं तन्मा अभिगां मा अभिगच्छेयम् ।द्विर्वचनमत्यन्तार्थहेतुत्वप्रदर्शनार्थम् ॥
In plain words
The Self, known as the inner consciousness of all living beings and self-revealing, is to be understood as Brahman—bodyless and all-pervading like space. That Self is Brahman, immortal and deathless. Hence the mantra: 'I enter the assembly and dwelling built by Lord Brahmā. I am the glory of brahmins, for they worship Him with special devotion. I become their glory, and likewise for kings and merchants, who are also eligible. That glory I wish to attain.' I am the self behind all the glories of the body, senses, mind, and intellect. Why do I approach thus? The text explains: May I never draw near to that slimy, slippery, reddish-white apparition—toothless yet devouring, wearing feminine forms, which strips away the splendor and strength of those who serve it. The repetition in the text emphasizes this supreme avoidance.
Close to the Sanskrit
The Self, indeed, known by name as the inner consciousness of all beings and self-revealing, is to be understood as Brahman, bodyless and all-pervading like space. And that Self is Brahman, immortal and deathless. Hence the following mantra: 'I reach the assembly and dwelling built by the Lord, the four-faced Prajāpati. Furthermore, I become the glory of brahmins, for brahmins worship [Him] specially, therefore I become their glory. Likewise for kings and merchants; since they are also eligible, I become their glory too. That glory I desire to attain.' Indeed, I am the self of all glories belonging to the body, senses, mind, and intellect. For what purpose do I approach thus? It is said: [Avoiding] that which is whitish in color, resembling a ripe jujube, reddish, toothless yet a consumer, having feminine marks, the destroyer of the splendor, strength, valor, and knowledge of those who serve it—that whitish, slimy, and slippery thing, may I not approach it, may I not draw near to it. The doubling of words is to show the reason for an extreme sense.