Shatapatha Brahmana 7.1.1.27

7.1.1.27

atha jaghanena parītya | uttarato dakṣiṇāsīno 'parayordakṣiṇāmagra upadadhātīḍāmagne purudaṃsaṃ saniṃ goriti paśavo vā iḍā paśūnāmevāsmā etāmāśiṣamāśāste śaśvattamaṃ havamānāya sādheti yajamāno vai havamānaḥ syānnaḥ sūnustanayo vijāveti prajā vai sūnuragne sā te sumatirbhūtvasme ityāśiṣamāśāste

Thereupon going round behind, he sits down on the north side with his face to the south, and puts on first the southern one of the two behind, with (Vâg. S. XII, 51), 'Potent nourishment, O Agni, the possession of kine,'--nourishment means cattle: he thus invokes for him the blessing of cattle;--'Grant thou perpetually unto him that calleth!'--he that calls doubtless is the Sacrificer; 'May there be to us a son, the perpetuator of the race,'--a son means offspring;--'let that, O Agni, be thy good-will unto us!' he therewith invokes a blessing.