Bhashya
रूपवद्द्रव्ये सर्वस्य दर्शनात् ।कथम् ? तेजसि तावद्रूप-वति शब्दस्पर्शयोरप्युपलम्भात् वायुवन्तरिक्षयोः तत्र स्पर्श-शब्दगुणवतोः सद्भावो अनुमीयते ।तथा अबन्नयोः रूप-वतो रसगन्धान्तर्भाव इति ।रूपवतां त्रयाणां तेजोबन्नानांत्रिवृत्करणप्रदर्शनेन सर्वं तदन्तर्भूतं सद्द्विकारत्वान् त्रीण्येवरूपाणि विज्ञातं मन्यते श्रुतिः ।न हि मूर्ते रूपवद्द्रव्यं प्र-त्याख्याय वायुवाकाशयोः तद्गुणयोर्गन्धवतोर्वा ग्रहणमस्ति ।अथवा रूपवतामपि त्रिवृत्करणं प्रदर्शनार्थमेव मन्यते श्रुतिः ।यथा तु त्रिवृत्कृते त्रीणि रूपाणीत्येव सत्यम् , तथा पञ्चीक-रणेऽपि समानो न्याय इत्यतः सर्वस्य सद्द्विकारत्वात् सताविज्ञातेन सर्वमिदं विज्ञातं स्यात् सद्देकमेवाद्वितीयं सत्य-मिति सिद्धमेव भवति ।तदेकस्मिन्सति विज्ञाते सर्वमिदंविज्ञातं भवतीति सूक्तम् ॥
In plain words
Because everything is perceived in a substance that possesses form. How? In fire, which has form, sound and touch are also found; in air and space, the presence of those elements possessing touch and sound is inferred. Similarly, in water and earth, which have form, taste and smell are included. Through the demonstration of the triplication of these three formed elements, the scripture considers all of them to be encompassed, since they are modifications of Being and only three forms are recognized. For without dismissing corporeal substances having form, there is no grasping of air and space or their respective qualities. Or rather, the scripture treats the triplication of formed things merely as an illustrative device. Just as the triplication resulting in three forms is true, the same logical rule applies to pentuplication. Therefore, since everything is a modification of Being, knowing Being means knowing this entire universe, establishing that Reality is one alone, without a second. Thus the scriptural declaration that knowing the One makes everything known is entirely apt.
Close to the Sanskrit
Because of the perception of everything in a substance having form. How? In fire possessing form, since sound and touch are also perceived; in air and space, there the existence of those two having touch and sound qualities is inferred. Similarly, of water and food, the inclusion of taste and smell because they have form. Considering the triplication demonstration of the three elements having form, the Sruti considers everything included therein to be known since they are modifications of Being, and only three forms are known. Indeed, without rejecting corporeal substance having form, there is no apprehension of air and space or their qualities of smell. Or else the Sruti considers the triplication of formed things merely for demonstration. Just as when triplicated, three forms alone are true, similarly the rule is identical in pentuplication; hence, since all is a modification of Being, by the knowledge of Being this entire universe would be known, and it stands established that Being is one alone, without a second, true. That when the one is known, this entire universe is known, is well-said.