Śatapatha Brāhmaṇa ("of a hundred paths") 1.3.4.6

1.3.4.6

so 'bhyādadhāti | vītihotraṃ tvā kave dyumantaṃ samidhīmahi agne bṛhantamadhvara ityetayā gāyatryā gāyatrīmevaitatsamindhe sā gāyatrī samiddhānyāni candāṃsi samindhe candāṃsi samiddhānidevebhyo yajñaṃ vahanti

He puts it on, with the gâyatrî stanza (Vâg. S. II, 4), 'Thee, O Sage, who callest (the gods) to the feast, we will kindle so as to shine brilliantly; thee, O Agni, mighty at the sacrifice!' He thereby kindles the gâyatrî; the gâyatrî, when kindled, kindles the other metres; and the metres, when kindled, carry the sacrifice to the gods.