The Mukhya Upaniṣads

Maitrī · Prapāṭhaka 5 · Maitrī 5.1

Passage 6

अथ व्यात्तं वा इदमासीत्सत्यं प्रजापतिस्तपस्तप्त्वा अनुव्याहरद्भूर्भुवःस्वरित्येषा हाथ प्रजापतेः स्थविष्ठा तनूर्वा लोकवतीति स्वरित्यस्याः शिरो नाभिर्भुवो भूः पादा आदित्यश्चक्षुरायत्तः पुरुषस्य महतो मात्राश्चक्षुषा ह्ययं मात्राश्चरिति सत्यं वै चक्षुरक्षिण्युपस्थितो हि पुरुषः सर्वार्थेषु वदत्येतस्माद्भूर्भुवःस्वरित्युपासीतान्नं हि प्रजापतिर्विश्वात्मा विश्वचक्षुरिवोपासितो भवतीत्येवं ह्याहैषा वै प्रजापतिर्विश्वभृत्तनूरेतस्यामिदं सर्वमन्तर्हितमस्मि ।चंश्च सर्वस्मिन्नेषान्तर्हितेति तस्मादेषोपासीतेति ॥५.६ ॥

In plain words

Now this was unuttered. The real, Prajāpati, having performed austerity, uttered forth bhūḥ, bhuvaḥ, svaḥ. This is the coarsest body of Prajāpati, the one that has the worlds: svaḥ is its head, bhuvaḥ its navel, bhūḥ its feet, and the sun its eye. For upon the eye depends the great measure of a person, since it is by the eye that he moves among measures. The eye indeed is the real; for the person seated in the eye moves among all objects. Therefore let a man worship with bhūḥ, bhuvaḥ, svaḥ; for by that Prajāpati is worshipped as the self of all, as the eye of all. So it is said: "This is the world-bearing body of Prajāpati; in it all this is hidden, and it is hidden in all this. Therefore let a man worship this."