Bhashya
लोकेऽपि यस्मिन् हि यदाश्रितं भवति, तस्मादाश्रितात् आश्र-यस्य बलवत्तरत्वं प्रसिद्धम् ; न हि दुर्बलं बलवतः कचित्आश्रयभूतं दृष्टम् ; एवं उक्तन्यायेन उ एषा गायत्री अध्या-त्मम् अध्यात्मे प्राणे प्रतिष्ठिता ; सैषा गायत्री प्राणः ; अतोगायत्र्यां जगत्प्रतिष्ठितम् ; यस्मिन्प्राणे सर्वे देवा एकं भवन्ति,सर्वे वेदाः, कर्माणि फलं च ; सैवं गायत्री प्राणरूपा सतीजगत आत्मा ।सा ह एषा गयान् तत्रे त्रातवती ; के पुनर्ग-याः? प्राणाः वागादयः वै गयाः, शब्दकरणात् ; तान् तत्रे सैषागायत्री ।तत् तत्र यत् यस्मात् गयान् तत्रे, तस्मात् गायत्रीनाम ; गयत्राणात् गायत्रीति प्रथिता ।स आचार्यः उपनीयमाणवकमष्टवर्षं यामेव अमूं गायत्रीं सावित्रीं सवितृदेवता-काम् अन्वाह पच्छः अर्धर्चशः समस्तां च, एषैव स सा-क्षात् प्राणः जगत आत्मा माणवकाय समर्पिता इह इदानींव्याख्याता, नान्या ; स आचार्यः यस्मै माणवकाय अन्वाहअनुवक्ति, तस्य माणवकस्य गयान् प्राणान् त्रायते नरका-दिपतनात् ॥
In plain words
Even in ordinary life, whatever depends on something else tells you the thing it depends on is the stronger of the two — a weak thing never holds up a strong one. Apply that here: this Gāyatrī, seen in the body, rests on the breath of life. This Gāyatrī simply is the breath. Which means the whole world rests in her — because in that one breath, all the gods become one, the whole Veda becomes one, every action and its fruit become one. As the breath, she is the very Self of the world. And she protected the gayas she gathered to herself — protected them, that's the word. Who are the gayas? Speech and the other senses — they are called that because they are what makes sound possible. She protected them, and that protecting is exactly why she is named Gāyatrī: gaya-trāṇa, 'protector of the gayas.' A teacher initiates a boy of eight and recites this very verse to him — foot by foot, half-line by half-line, and whole — because it is nothing less than the breath itself, the Self of the world, being handed to him now. Not some other verse: this one. And whatever pupil a teacher recites it to, that pupil's own breath, his own life, is protected from falling into hell or anything like it.
Close to the Sanskrit
In the world too, wherever something dependent exists, it is well known that, from that dependent thing, its support is the more powerful — for a weak thing is never seen anywhere to be the support of a strong one. By this stated reasoning, this very Gāyatrī, with respect to the body, is established in the breath that pertains to the body. This very Gāyatrī is the breath. Therefore the world is established in the Gāyatrī. In that breath all the gods become one, all the Vedas, actions, and their fruit. Thus this Gāyatrī, having the nature of the breath, is the Self of the world. She, this one, protected the gayas she drew to herself. But who, then, are the gayas? The breaths — speech and the rest — indeed are the gayas, because of their function of producing sound. She protected them, this very Gāyatrī. Because there, for the reason that she protected the gayas, therefore [she is called] Gāyatrī by name — she became renowned as Gāyatrī from 'the protection of the gayas.' The teacher, having initiated the eight-year-old boy, recites to him this very Gāyatrī, called Sāvitrī, whose deity is Savitṛ — foot by foot, half-verse by half-verse, and whole; this very one, who is directly the breath, the Self of the world, is now here explained to the pupil — no other. That teacher, to whatever pupil he recites it, protects that pupil's gayas, his breaths, from falling into hell and the like.