यः पूर्वं तपसो जातमद्भ्यः पूर्वमजायत ।
गुहां प्रविश्य तिष्ठन्तं यो भूतेभिर्व्यपश्यत । एतद्वै तत् ॥ ६ ॥

yaḥ pūrvaṃ tapaso jātamadbhyaḥ pūrvamajāyata |
guhāṃ praviśya tiṣṭhantaṃ yo bhūtebhirvyapaśyata | etadvai tat || 6 ||

Who sees him seated within the five elements,—him who was born of Tapas (Brahman) who was born before the waters and who having entered the cavity of the heart, is therein seated. This verily is that.

Shankara’s Commentary:

This shows that he who was pointed as the pratyagatman and Isvara is the atman of all. Yah some seeker after emancipation. Purvam first. Tapasah from the Brahman defined as knowledge, etc. Jatam created or produced, the first-born of Brahman, i.e., Hiranyagarhha. ‘Born before whom’ is explained. Adbhyah purvam before the five elements, including water; not before water alone; ajayata was born. This first-born who having created the bodies of the Devas, etc., entered the akas of the heart of every living thing and is there seated, perceiving sounds, etc., Bhutebhih means Bhutah or elements in the nature of cause and effect. Who sees him seated with them: who sees thus. See this alone, i.e., Brahman the subject of our present discussion.