Bhashya
हे याज्ञवल्क्येत्येवं संबोध्य अभिमुखीकरणाय, किंज्यो-तिरयं पुरुष इति—किमस्य पुरुषस्य ज्योतिः, येन ज्योतिषाव्यवहरति ? सोऽयं किंज्योतिः ? अयं प्राकृतः कार्यक-रणसंघातरूपः शिरःपाण्यादिमान् पुरुषः पृच्छ्यते- किमयंस्वावयवसंघातबाह्येन ज्योतिरन्तरेण व्यवहरति, आहोस्वित्स्वावयवसंघातमध्यपातिना ज्योतिषा ज्योतिष्कार्यम् अयंपुरुषो निर्वर्तयति- इत्येतदभिप्रेत्य- पृच्छति ।किंचातः,यदि व्यतिरिक्तेन यदि वा अव्यतिरिक्तेन ज्योतिषा ज्योति-ष्कार्य निर्वर्तयति ? शृणु तत्र कारणम्- यदि व्यतिरिक्ते-नैव ज्योतिषा ज्योतिष्कार्यनिर्वर्तकत्वम् अस्य स्वभावो निर्धा-रितो भवति, ततः अदृष्टज्योतिष्कार्यविषयेऽप्यनुमास्यामहेव्यतिरिक्तज्योतिर्निमित्तमेवेदं कार्यमिति; अथाव्यतिरिक्तेनैवस्वात्मना ज्योतिषा व्यवहरति, ततः अप्रत्यक्षेऽपि ज्योतिषिज्योतिष्कार्यदर्शने अव्यतिरिक्तमेव ज्योतिः अनुमेयम्; अथा-नियम एव- व्यतिरिक्तम् अव्यतिरिक्तं वा ज्योतिः पुरुषस्यव्यवहारहेतुः, ततः अनध्यवसाय एव ज्योतिर्विषये-इत्येवं मन्वानः पृच्छति जनको याज्ञवल्क्यम्- किं ज्योति-रयं पुरुष इति ।ननु एवमनुमानकौशले जनकस्य किंप्रश्नेन, स्वयमेव कस्मान्न प्रतिपद्यत इति- सत्यमेतत् ;तथापि लिङ्गलिङ्गिसंबन्धविशेषाणामत्यन्तसौक्ष्म्यात् दुरव-बोधतां मन्यते बहूनामपि पण्डितानाम्, किमुतैकस्य; अतएव हि धर्मसूक्ष्मनिर्णये परिषद्व्यापार इष्यते, पुरुषविशेष-श्चापेक्ष्यते- दशावरा परिषत्, त्रयो वा एको वेति;तस्मात् यद्यपि अनुमानकौशलं राज्ञः, तथापि तु युक्तो या-ज्ञवल्क्यः प्रष्टुम्, विज्ञानकौशलतारतम्योपपत्तेः पुरुषा-णाम् ।अथवा श्रुतिः स्वयमेव आख्यायिकाव्याजेन अनु-मानमार्गमुपन्यस्य अस्मान्बोधयति पुरुषमतिमनुसरन्ती ;याज्ञवल्क्योऽपि जनकाभिप्रायाभिज्ञतया व्यतिरिक्तमात्म-ज्योतिर्बोधयिष्यन् जनकं व्यतिरिक्तप्रतिपादकमेव लिङ्गंप्रतिपेदे, यथा- प्रसिद्धमादित्यज्योतिः सम्राट् इति होवा-च ।कथम्? आदित्येनैव स्वावयवसंघातव्यतिरिक्तेन चक्षु-षोऽनुग्राहकेण ज्योतिषा अयं प्राकृतः पुरुषः आस्ते उपवि-शति, पल्ययते पर्येति क्षेत्रमरण्यं वा, तत्र गत्वा कर्मकुरुते, विपल्येति विपर्येति च यथागतम् ।अत्यन्तव्यतिरि-क्तज्योतिष्प्रसिद्धताप्रदर्शनार्थम् अनेकविशेषणम्; बाह्यानेक-ज्योतिःप्रदर्शनं च लिङ्गस्याव्यभिचारित्वप्रदर्शनार्थम् ।एव-मेवैतद्याज्ञवल्क्य ॥
In plain words
He calls him by name, "Yājñavalkya," simply to turn his attention to the question: "What light does this person live by?" -- meaning, what is it that lets him act at all? Put plainly: does this ordinary person, this bundle of body and organs with his head and hands and all the rest, run on a light outside that bundle, or on a light hidden somewhere inside it? That is the real question behind the question. And it matters which, for this reason: if his nature is fixed so that only an outside light ever does this work, then even in cases we've never watched, we can safely infer an outside light at work. But if he runs on a light that simply is himself, then even without seeing that light directly, seeing its effects tells us it must be that same, inseparable kind. And if there's no rule at all -- if either kind of light could just as well explain him -- then nothing can be concluded, and the whole question collapses into guesswork. This is exactly the bind Janaka is thinking through when he puts the question to Yājñavalkya. Now, someone might object: if Janaka can reason this well on his own, why ask at all? Fair enough -- but the threads connecting a sign to what it signals are so fine that even a room full of scholars can find them hard to follow, let alone one mind working alone. That is exactly why, in matters of subtle dharma, tradition calls for a panel to decide -- and specifically qualified people at that: a panel of ten or more, or three, or, at the very least, one truly exceptional judge. So even a king skilled in reasoning does well to ask Yājñavalkya, because people's powers of understanding are never all the same. Or look at it another way: scripture itself is telling this as a story precisely to walk us through the reasoning, meeting the mind where it actually works. And Yājñavalkya, for his part, knowing exactly what Janaka was getting at, chose his answer to prove the very point Janaka needed proved -- that the light in question is genuinely separate from the body. That's why he said, "The familiar sunlight, your majesty." Think about what that means: by sunlight alone -- a light plainly outside his own limbs, which simply helps the eye see -- this ordinary person sits down, walks out across a field or into the woods, does his work there, and comes back the way he came. All those details are there to show just how firmly established this outside light is. And naming several such outside lights, one after another, is there to prove the sign never fails -- it points the same way every time. "Just so, Yājñavalkya."
Close to the Sanskrit
By addressing him thus, "O Yājñavalkya," in order to turn him to face the question: "What light has this person?" -- that is, what is this person's light, by which light he acts? This person -- what light does he have? This ordinary person, in the form of an aggregate of effects and instruments, possessing a head, hands, and so on, is being asked about: does he act by a light external to the aggregate of his own limbs, or does this person accomplish the work of light by a light falling within that aggregate? With this in mind he asks. And further: does he accomplish the work of light by a light that is distinct [from the body], or by one that is not distinct? Hear the reason this matters: if it is settled that his nature is to accomplish the work of light only by a distinct light, then even where the effect of light is not directly observed, we shall infer that a distinct light alone is its cause; but if he acts by a light not distinct from his own self, then even without perceiving the light itself, upon seeing the effect of light we must infer only a non-distinct light; but if there is simply no fixed rule -- if either a distinct or a non-distinct light could equally cause the person's activity -- then there is simply no way to settle the matter of this light at all. Thinking in this way, Janaka asks Yājñavalkya: "What light has this person?" But surely, given such skill at inference, what need has Janaka of asking -- why does he not work it out himself? This is true; nevertheless, on account of the extreme subtlety of the relations between an inferential mark and what it marks, [Śaṅkara] holds this hard to grasp even for many learned men together, let alone for one man alone; that is precisely why, in settling subtle points of dharma, the judgment of an assembly is required, and a person of particular qualification is likewise required -- an assembly of not fewer than ten, or three, or even one [outstanding individual]. Therefore, although the king has skill at inference, it is still proper for him to ask Yājñavalkya, since gradation in skill of understanding among men is simply a fact. Or alternatively: scripture itself, under the guise of a story, lays out the path of inference and instructs us by following the pattern of human reasoning. Yājñavalkya too, aware of Janaka's intention, and intending to make known the distinct light of the Self, resorted, in replying to Janaka, to precisely a mark that establishes distinctness -- as when he said, "The well-known sunlight, O emperor." How so? By the sun's light alone -- a light distinct from the aggregate of his own limbs, which aids the eye -- this ordinary person sits, that is, seats himself; goes about, that is, goes around a field or a forest; having gone there, performs work; and returns, that is, comes back, the way he came. The many qualifying words are for the purpose of showing how well-established a light utterly distinct [from the body] is; and the demonstration of many external lights [to follow] is for the purpose of showing the invariable reliability of this inferential mark. "Just so, Yājñavalkya."