Shatapatha Brahmana 6.3.1.38

6.3.1.38

tāmādatte | devasya tvā savituḥ prasave 'śvinorbāhubhyām vitṛprasūta evaināmetadetābhirdevatābhirādatte gāyatreṇapūṣṇo hastābhyāmādade gāyatreṇa candasāṅgirasvaditi sa candasātho asyāṃ gāyatraṃ cando dadhāti pṛthivyāḥ sadhasthādagnim purīṣyamaṅgirasvadābhareti paśavo vai purīṣam pṛthivyā upasthādagnim paśavyamagnivadābharetyetattraiṣṭubhena candasāṅgirasvaditi tadenāṃ traiṣṭubhena candasādatte 'tho asyāṃ traiṣṭubhaṃ cando dadhāti

He takes it up, with (Vâg. S. XI, 9), 'At the impulse of the god Savitri, I take thee by the arms of the Asvins, by the hands of Pûshan, by the Gâyatrî metre, Aṅgiras-like!' By means of those deities he thus takes it up, impelled by Savitri; by the Gâyatrî metre: he thus imparts the Gâyatrî metre to it. 'From the Earth's seat, Aṅgiras-like, bring thou Agni Purîshya!'-- now soil means cattle: thus, 'from the earth's lap bring thou Agni, favourable to cattle, as Agni (did)!'--'by the Trishtubh metre, Aṅgiras-like!' he thereby takes it with the Trishtubh metre and thus lays into it the Trishtubh metre.