Bhashya
शान्तायां पुनर्वाचि, गन्धादिष्वपि च शान्तेषु बाह्येष्व-नुग्राहकेषु, सर्वप्रवृत्तिनिरोधः प्राप्तोऽस्य पुरुषस्य ।एतदुक्तंभवति— जाग्रद्विषये बहिर्मुखानि करणानि चक्षुरादीनिआदित्यादिज्योतिर्भिरनुगृह्यमाणानि यदा, तदा स्फुटतरःसंव्यवहारोऽस्य पुरुषस्य भवतीति ; एवं तावत् जागरितेस्वावयवसंघातव्यतिरिक्तेनैव ज्योतिषा ज्योतिषकार्यसिद्धि-रस्य पुरुषस्य दृष्टा ; तस्मात् ते वयं मन्यामहे- सर्वबाह्य-ज्योतिःप्रत्यस्तमयेऽपि स्वप्नसुषुप्तकाले जागरिते च तादृ-गवस्थायां स्वावयवसंघातव्यतिरिक्तेनैव ज्योतिषा ज्योति-ष्कार्यसिद्धिरस्येति ; दृश्यते च स्वप्ने ज्योतिषकार्यसिद्धिः-बन्धुसंगमनवियोगदर्शनं देशान्तरगमनादि च ; सुषुप्ताच्चउत्थानम्- सुखमहमस्वाप्सं न किंचिदवेदिषमिति ; तस्मा-दस्ति व्यतिरिक्तं किमपि ज्योतिः ; किं पुनस्तत् शान्तायांवाचि ज्योतिः भवतीति ।उच्यते—आत्मैवास्य ज्योतिर्भव-तीति ।आत्मेति कार्यकारणस्वावयवसंघातव्यतिरिक्तं कार्य-करणावभासकम् आदित्यादिबाह्यज्योतिर्वत् स्वयमन्येनानव-भास्यमानम् अभिधीयते ज्योतिः ; अन्तःस्थं च तत् पारि-शेष्यात्- कार्यकारणव्यतिरिक्तं तदिति तावत्सिद्धम् ; यच्च
In plain words
Now take it a step further: once even speech has gone quiet, and the other senses that usually help us -- smell and the rest -- have gone quiet too, all activity in this person simply stops. Here is what that means. In waking life, when the outward-facing senses, the eye and the others, are lit up by the sun and its kin, a person's dealings with the world grow sharp and clear. So in the waking state, at least, we've watched a light other than the body's own limbs doing its work. That's why we hold this: even when every outer light has gone dark -- in dream, in deep sleep, and even in that same darkened waking state -- a light other than the body's own parts is still doing its work. You can see it happen in dream: meeting a relative, parting from one, travelling to distant places. You can see it in the very act of waking from deep sleep, in the thought, 'I slept well; I wasn't aware of a thing.' So some light distinct from the body clearly exists. But then what is that light, once even speech has fallen silent? Here is the answer: the Self alone is his light. 'The Self' is the name for that light which stands apart from the whole assembly of the body's own limbs, which lights up the body and its instruments the way sunlight lights up the world outside -- except that nothing else ever has to light it up. That is what deserves the name light. And it sits within; by simple elimination we've now shown it is distinct from both effect and instrument. And as for what--
Close to the Sanskrit
Now, when speech too has become quiet, and when the external, assisting senses -- smell and the rest -- have also become quiet, a cessation of all activity has befallen this person. This is what is meant: when, in the domain of the waking state, the outward-facing organs such as the eye are being aided by the lights of the sun and so on, then this person's transactions with the world become clearer. So far, then, in the waking state, the accomplishment of the light's function by a light other than the aggregate of his own limbs has been observed for this person. Therefore we hold this: even when all external lights have set, in the time of dream and of deep sleep, and even in waking under that same condition, the accomplishment of the light's function by a light other than the aggregate of his own limbs occurs for him. And indeed the accomplishment of the light's function is seen in dream -- the perceiving of meeting and parting with kinsmen, going to other lands, and so on. And also the rising from deep sleep with the thought: 'I slept happily; I was not aware of anything at all.' Therefore some light distinct from the body does exist. But then, what is that light when speech too has become quiet? It is said: the Self alone is his light. 'The Self' is the term applied to that light which is distinct from the aggregate of one's own limbs -- the effect and instrument -- which illumines effect and instrument, and which, like the external light of the sun and so on, is itself not illumined by anything else; it is called light. And it is situated within; by the process of elimination it has thus far been established that it is distinct from effect and cause. And that which--