Śatapatha Brāhmaṇa ("of a hundred paths") 3.4.1.23

3.4.1.23

sa manthati | gāyatreṇa tvā candasā manthāmi traiṣṭubhena tvā candasā manthāmi jāgatena tvā candasā mānthāmīti taṃ vai candobhireva manthati candāṃsi mathyamānāyānvāha candāṃsyevaitadyajñamanvāyātayati yathāmumādityaṃ raśmayo jātāyānubrūhītyāha yadā jāyate prahriyamāṇāyetyanupraharan

He churns, with the texts, 'With the Gâyatrî metre I churn thee!--With the Trishtubh metre I churn thee!--With the Gagatî metre I churn thee!' For it is with the metres that he churns him (Agni, the fire); the metres he recites to him when he is churned, whereby he attaches the metres to the sacrifice, even as the rays (are attached) to yonder sun.--'Recite to the born one!' he says, when he (Agni) is produced; and 'To him who is thrown!' when he throws him (on the old Âhavanîya fire).