तौ ह प्रजापतिरुवाच य एषोऽक्षिणि पुरुषो दृश्यत एष आत्मेति होवाचैतदमृतमभयमेतद्ब्रह्मेत्यथ योऽयं भगवोऽप्सु परिख्यायते यश्चायमादर्शे कतम एष इत्येष उ एवैषु सर्वेष्वन्तेषु परिख्यायत इति होवाच ॥ ८.७.४ ॥
In plain words
Prajāpati said to them, "The person who is seen in the eye — that is the Self," he said; "that is the immortal, the fearless; that is Brahman." "But, sir, this one who is seen in water and this one in a mirror — which of these is it?" "This same one is seen in all these," he said.
The commentators
Chāndogyopaniṣadbhāṣyam· Leaf 7.321· bhāṣya
तौ ह गत्वा द्वात्रिंशतं वर्षाणि शुश्रूषापरौ भूत्वा ब्रह्म- चर्यम् ऊषतुः उषितवन्तौ । अभिप्रायज्ञः प्रजापतिः तावु- वाच—किमिच्छन्तौ किं प्रयोजनमभिप्रेय इच्छन्तौ अवास्तम् उषितवन्तौ युवामिति । इत्युक्तौ तौ ह ऊचतुः—य आत्मे- त्यादि भगवतो वचो वेदयन्ते शिष्टाः, अतः तमात्मानं ज्ञातु- मिच्छन्तौ अवास्तमिति । यद्यपि प्राक्प्रजापतेः समीपामम - समन्तात् ज्ञायते, यश्चायमादर्शे आत्मनः प्रतिबिम्बाकारः परिख्यायते खङ्गादौ च, कतम एष एषां भगवद्भिरुक्तः, किं वा एक एव सर्वेष्विति । एवं पृष्टः प्रजापतिरुवाच— एष उ एव यश्चक्षुषि द्रष्टा मयोक्त इति । एतन्मनसि कृत्वा एषु सर्वेष्वन्तेषु मध्येषु परिख्यायते इति ह उवाच ॥
In plain words
Going to Prajāpati, the two devoted themselves to service and lived as students for another thirty-two years. Knowing their intent, Prajāpati asked: 'With what desire and purpose have you lived here?' They replied: 'Knowing the venerable one's teaching about the Self, we have stayed here wishing to realize that Self. We see that a reflection of the body appears in a mirror or on a sword blade—which of these is the Self you spoke of, or is it one and the same in all?' Thus questioned, Prajāpati answered: 'This very one is the seer whom I described as dwelling in the eye.' Bearing this in mind, he declared that the Self is clearly perceived across all these forms.
Close to the Sanskrit
Those two indeed having gone, having become devoted to service for thirty-two years, lived the life of a student. Prajāpati knowing their intent spoke to them: 'Desiring what, with what purpose in mind, did you two reside here?' Thus addressed, those two said: 'As the competent authorities understand the venerable one's teaching beginning with "The Self...", desiring to know that Self we have dwelt here.' Although prior to Prajāpati's presence it is fully known that this reflected form of the self is seen in a mirror and in a sword blade etc., which one precisely among these is this declared by your reverences, or is it one alone across all? Thus questioned, Prajāpati spoke: 'This very one is he who is spoken of by me as the seer in the eye.' Keeping this in mind, he spoke: 'He is clearly seen in all these ends and middles.'
Chāndogyopaniṣadbhāṣyam· Leaf 7.323· bhāṣya
ननु कथं युक्तं शिष्ययोर्विपरीतग्रहणमनुज्ञातुं प्रजापतेः विगतदोषस्य आचार्यस्य सतः ? सत्यमेवम्, नानुज्ञातम् । कथम् ? आत्मन्यध्यारोपितपाण्डित्यमहत्त्वबोद्धृत्वौ हि इन्द्र- विरोचनौ, तथैव च प्रथितौ लोके ; तौ यदि प्रजापतिना 'मूढौ युवां विपरीतग्राहिणौ' इत्युक्तौ स्याताम् ; ततः तयोश्चि- त्ते दुःखं स्यात् ; तज्जनिताच्च चित्तावसादात् पुनःप्रश्नश्रवण- ग्रहणावधारणं प्रति उत्साहविघातः स्यात् ; अतो रक्षणीयौ शिष्याविति मन्यते प्रजापतिः । गृहीतां तावत्, तदुदशराव- दृष्टान्तेन अपनेष्यामीति च । ननु न युक्तम् एष उ एव इत्यनृतं वक्तुम् । न च अनृतमुक्तम् । कथम् ? आत्मनोक्तः अक्षि- पुरुषः मनसि संनिहिततरः शिष्यगृहीताच्छायात्मनः ; सर्वेषां चाभ्यन्तरः 'सर्वान्तरः' इति श्रुतेः ; तमेवावोचत् एष उ एव इति ; अतो नानृतमुक्तं प्रजापतिना ॥
In plain words
Now, how could a flawless teacher like Prajāpati allow his disciples to misunderstand? True, he did not allow it by design. Indra and Virocana considered themselves learned and great, and were renowned as such. Had Prajāpati bluntly told them they were foolish and mistaken, distress would have entered their minds. From that discouragement, their zeal for asking, listening, and retaining instruction would have withered. Realizing this, Prajāpati thought: 'These disciples must be protected. Let them hold their view for now; I will dispel their delusion using the water-pan illustration.' But wasn't it wrong for him to utter an untruth by saying 'This one alone'? No, no untruth was spoken. Why? Because the conscious person in the eye, whom Prajāpati had in mind, was far more immediate and real than the crude shadow-self the disciples had grasped. Furthermore, as scripture declares, he is the 'innermost of all.' Prajāpati was teaching that very truth, so no falsehood was spoken.
Close to the Sanskrit
Now then, how is it proper for a faultless teacher, Prajāpati, to permit the pupils' misunderstanding? True thus, it was not permitted. How? Indra and Virocana fancied themselves possessed of superimposed scholarship, greatness, and understanding, and were thus renowned in the world; if they had been told by Prajāpati 'You two are foolish, holding perverted views,' then distress would arise in their minds, and from that mental depression there would occur a destruction of enthusiasm regarding repeated questioning, listening, grasping, and retention. Therefore, Prajāpati considers, the disciples must be protected. Let them hold their view for now, I will remove it through that example of the water vessel. Now, is it not improper to utter an untruth saying 'This very one alone'? But no untruth was spoken. How? The person in the eye spoken of in relation to the Self was far more immediate in his mind than the shadow-self grasped by the disciples; and he is the innermost of all, as śruti states 'the innermost of all.' He spoke precisely of that one, saying 'This very one alone.' Therefore no untruth was spoken by Prajāpati.