Bhashya
मूर्तामूर्तात्मकं जगत् त्रिपदा गायत्री आदित्ये प्रतिष्ठिता तद्व-सत्त्वात् सह त्रिभिः पादैः, तद्वै तुरीयं पदं सत्ये प्रतिष्ठि-तम् ; किं पुनः तन् सत्यमित्युच्यते- चक्षुर्वै सत्यम् ।कथचक्षुः सत्यमित्याह- प्रसिद्धमेतत्, चक्षुर्हि वै सत्यम् ।कथंप्रसिद्धेतेत्याह-तस्मात्-यत् यदि इदानीमेव द्वौ विवद-मानौ विरुद्धं वदमानौ एयाताम् आगच्छेयाताम् ; अहम्अदर्शी दृष्टवानस्मीति अन्य आह ; अहम् अश्रौषम्- त्वयादृष्टं न तथा तद्वस्तीति ; तयोः य एवं ब्रूयात्-'अहमद्राक्षमिति, तस्मै एव श्रद्दध्याम ; न पुनः यःब्रूयात् अहमश्रौषमिति ; श्रोतुः मृषा श्रवणमपि संभ-वति ; न तु चक्षुषो मृषा दर्शनम् ; तस्मात् न अ-श्रौषमित्युक्तवते श्रद्दध्याम ; तस्मात् सत्यप्रतिपत्तिहेतु-त्वात् सत्यं चक्षुः ; तस्मिन् सत्ये चक्षुषि सह त्रिभिः इतरैःपादैः तुरीयं पदं प्रतिष्ठितमित्यर्थः ।उक्तं च 'स आदित्यःकस्मिन्प्रतिष्ठित इति चक्षुषीति' ।तद्वै तुरीयपदाश्रयं सत्यंबले प्रतिष्ठितम् ; किं पुनः तत् बलमित्याह- प्राणो वैबलम् ; तस्मिन्प्राणे बले प्रतिष्ठितं सत्यम् ।तथा चोक्तम्-'सूत्रेतदोतं च प्रोतं च' इति ।यस्मात् बले सत्यं प्रतिष्ठितम्,तस्मादाहुः- बलं सत्यादोगीयाः ओजीयः ओजस्तरमित्यर्थः ;
In plain words
This world of everything with shape and everything without it — the Gāyatrī with her three feet stands on the sun, because that is where those three feet live. And the fourth foot stands on truth. So what is truth here? The eye is truth. Why? Because everyone already knows it. Think of two men arguing: one says, 'I saw it myself,' the other says, 'I only heard it wasn't so.' Trust the one who saw. Never the one who only heard — hearing can lie, sight cannot. That is why the eye, and nothing else, earns the name truth, and why the fourth foot rests there alongside the other three. There is even a saying for it: the sun itself rests on the eye. But truth rests on something further still — strength, which is to say, prāṇa, the breath of life. Everything is woven on that thread, warp and weft together. And because truth itself is woven on strength, the tradition says: strength outranks even truth.
Close to the Sanskrit
The world consisting of the formed and the formless — the three-footed Gāyatrī is established in the sun, because of its dwelling there, together with [its] three feet. That indeed is the fourth foot, established in truth. But what, then, is that truth? It is said: the eye indeed is truth. How is the eye truth? It is said: this is well known; the eye indeed is truth. How is it well known? It is said: because — if, right now, two men in dispute, saying contradictory things, should come before someone: one says, 'I saw — I have seen'; the other says, 'I heard — what you saw was not so.' Of the two, whoever should say, 'I have seen' — in him alone should we place faith, not in the one who says, 'I have heard.' For a hearer's hearing can also be false, but the eye's seeing is never false. Therefore we should not place faith in the one who has said 'I heard.' Therefore, because it is the ground for arriving at truth, the eye is truth. In that true eye, together with the other three feet, the fourth foot is established — this is the meaning. And it has been said: 'On what is that sun established? — On the eye, it is said.' That truth, the seat of the fourth foot, is established in strength. But what, then, is that strength? It is said: prāṇa indeed is strength. In that prāṇa, that strength, truth is established. And so it has been said: 'On the thread, that [world] is woven crosswise and lengthwise.' Because truth is established in strength, therefore they say: strength is more vigorous than truth — that is, more potent, most potent — this is the meaning.