Bhashya
सोऽयम् आत्मा प्रस्तुत:, यत्र यस्मिन्काले, अबल्यम् अबलभावम्, नि एत्य गत्वा— यत् देहस्य दौर्बल्यम्, तत् आत्मन एव दौर्बल्यमित्युपचर्यते ‘अबल्यं न्येत्य’ इति ; न ह्यसौ स्वतः अमूर्तत्वात् अबलभावं गच्छति— तथा सं- मोहमिव संमूढता संमोहः विवेकभावः संमूढतामिव न्येति निगच्छति ; न चास्य स्वतः संमोहः असंमोहो वा अस्ति, नित्यचैतन्यज्योतिःस्वभावत्वात् ; तेन इवशब्दः— संमोहमिव न्येतीति ; उत्क्रान्तिकाले हि करणोपसंहारनिमित्तो व्याकु-भ्यादानमित्युच्यते - सः यत्र एषः, चक्षुषि भवः चाक्षुषः पुरुषः आदित्यांशः भोक्तुः कर्मणा प्रयुक्तः यावद्देहधारणं तावत् चक्षुषोऽनुग्रहं कुर्वन् वर्तते ; मरणकाले तु अस्य चक्षुरनुग्रहं परित्यजति, स्वम् आदित्यात्मानं प्रतिपद्यते ; तदेतदुक्तम् - ' यत्रास्य पुरुषस्य मृतस्याग्निं वागप्येति वातं प्राणश्चक्षुरादित्यम् ' इत्यादि ; पुनः देहग्रहणकाले संश्रयिष्यन्ति ; तथा स्वप्स्यतः प्रबुध्यतश्च ; तदेतदाह - चाक्षुषः पुरुषः यत्र यस्मिन्काले, पराङ् पर्यावर्तते - परि समन्तात् पराङ् व्यावर्तते इति ; अथ अत्र अस्मिन्काले अरूपज्ञो भवति, मुमूर्षुः रूपं न जानाति ; तदा अयमात्मा चक्षुरादितेजोमात्राः समभ्याददानो भवति, स्वप्नकाल इव ॥
In plain words
This self we have been discussing — at the moment it sinks into feebleness, into real weakness — understand that the weakness actually belongs to the body; it is only spoken of, loosely, as the self's own weakness, which is why the text says 'come to feebleness.' The self itself, having no form to begin with, cannot literally weaken. In the same way, when it is said to go 'as if into confusion' — confusion here means only the loss of clear discernment — and 'as if' is the key word, because the self, eternal, conscious, luminous by its very nature, is never really confused or unconfused at all. What actually happens at the moment of departure is that the senses are withdrawing, and that withdrawal shows up as a kind of disturbance — that is all the phrase is pointing to. Now think of the part of you that sees through the eye: it is a fragment of the sun itself, stationed in the eye, doing the sun's own work of sight for as long as this body lasts. At death it simply lets that work go and returns to what it always was, sunlight. That is exactly what the old text means: at death, speech goes back into fire, breath into wind, the eye into the sun. And when a new body is taken up, they come back the same way — just as they do, in miniature, every time you fall asleep and every time you wake. When sight itself turns away like this, you stop knowing any form at all — that is simply what it is to be dying. And what remains, this self, gathers up the last of its light — beginning with the eye's own light — and carries it inward, exactly as happens, quietly, every night in dream.
Close to the Sanskrit
This self under discussion — when, at the time when, having gone to feebleness, to a weakened state — whatever weakness belongs to the body, that is figuratively spoken of as the weakness of the self alone; hence the phrase 'having come to feebleness'; for this self itself, being formless, does not itself go to a weakened state. Likewise, as to 'goes as if to confusion' — 'confusion' is confusedness, that is, the loss of the faculty of discernment; 'it goes, it attains what is like confusedness' — for this self itself has, of itself, neither confusion nor non-confusion, since its very nature is eternal, conscious light; hence the word 'iva' [as if] — '[goes] as if to confusion'; that is the meaning; for at the time of departure, owing to the withdrawal of the organs, a state of agitation arises, which is called merely a 'taking hold'. Now: when this person connected with the eye, a portion of the sun, existing in the eye, set to work by the enjoyer's action, as long as the body is maintained, remains conferring the function of the eye; but at the time of death he abandons the function of the eye and attains his own solar nature; and this indeed has been said: 'when, of this dying person, speech goes into fire, breath into wind, the eye into the sun', and so on; again, at the time of taking up a body, they will return to their source; likewise for one about to sleep and one waking up; and this indeed is stated: when this person connected with the eye turns backward — 'turns backward' meaning turns away completely on all sides — that is the meaning; then, at that time, he becomes one who does not know form, the one about to die does not know form; then this self, taking up together the particles of light beginning with the eye, becomes so, as at the time of dream.