तस्या उपस्थानम् ।गायत्र्यस्येकपदी द्विपदी त्रिपदी चतुष्पदि ।अपदसि ।न हि पद्यसे ।नमस्ते तुरीयाय दर्शताय पदाय परोरजसे ।असावदो मा प्रापदिति ।यं द्विष्यादसावस्मै कामो मा समर्धीति वा ।न हैवास्मै स कामः समृध्यते यस्मा एवमुपतिष्ठते ।अहमदः प्रापमिति वा ॥बृह. ५,१४.७ ॥
In plain words
The worship of her is this: "Gāyatrī, thou art of one foot, of two feet, of three feet, of four feet. Thou art without feet, for thou dost not go. Salutation to thy fourth, visible foot beyond the dust. May such a one never obtain his end" — if he hates someone, let him say, "May his desire not prosper," and the desire of the man against whom he thus worships does not prosper; or let him say, "May I obtain that end."
The commentators
Bṛhadāraṇyakopaniṣadbhāṣyam· bhāṣya
तस्या उपस्थानम्— तस्या गायत्र्याः उपस्थानम् उपेत्य स्थानं नमस्कारणम् अनेन मन्त्रेण । कोऽसौ मन्त्र इत्याह— हे गायत्रि असि भवसि त्रैलोक्यपादेन एकपदी, त्रयीविद्यारूपेण द्वितीयेन द्विपदी, प्राणादिना तृतीयेन त्रिपद्यसि, चतुर्थेन तुरीयेण चतुष्पद्यसि ; एवं चतुर्भिः पादैः उपासकैः पद्यसे ज्ञायसे ; अतः परं परेण निरुपाधिकेन स्वेन आत्मना
In plain words
Here is what worshipping her really means: drawing near, standing before her, paying homage — all through this one mantra. And what does the mantra say? 'Gāyatrī, you become one-footed through the three worlds, two-footed through the whole threefold Veda, three-footed through the breath of life and what goes with it, four-footed through the turīya, the fourth.' Through those four feet, a worshipper reaches you, comes to know you. But beyond even that four-footed form, there is something further still — the unconditioned, one's very own Self —
Close to the Sanskrit
Her worship [means]: the worship of this Gāyatrī — that is, the approaching, the standing, the performing of homage, by this mantra. What is that mantra? It is explained: 'O Gāyatrī, you are, you become, by the foot consisting of the three worlds, one-footed; by the second, the form of the threefold Veda, two-footed; by the third, [the foot] beginning with prāṇa, you are three-footed; by the fourth, the turīya, you are four-footed.' Thus, by these four feet, you are attained, you are known, by worshippers. Beyond this, however, by the further, unconditioned one, by [one's] own Self —