Shatapatha Brahmana 4.6.8.8

4.6.8.8

athedaṃ dvitīyam | araṇiṣvevāgnīntsamārohyopasamāyanti yatra prājāpatyena paśunā yakṣyamāṇā bhavanti mathitvopasamādhāyoddhṛtyāhavanīyaṃ yajanta etena prājāpatyena paśunā

Then there is this second. Having taken up their fires on churning-sticks, they betake themselves to where they intend to perform the animal offering to Pragâpati. Having churned (the fire), and put on (fire-wood), they take out the Âhavanîya and perform that animal offering to Pragâpati.