Śatapatha Brāhmaṇa ("of a hundred paths") 5.3.3.15

5.3.3.15

athāhāgnaye sviṣṭakṛte 'nubrūhīti | tadyadantareṇāhutī etatkarma kriyata eṣa vai prajāpatirya eṣa yajñastāyate yasmādimāḥ prajāḥ prajātā etamvevāpyetarhyanu prajāyantetadenam madhyata evaitasya prajāpaterdadhāti madhyataḥ suvati tasmādantareṇāhutī etatkarma kriyata āśrāvyāhāgnaye sviṣṭakṛte preṣyeti vaṣaṭkṛte juhoti

He now says, 'Pronounce the invitatory prayer to Agni Svishtakrit.' And as to why that ceremony is performed here between two offerings,--verily Pragâpati is that sacrifice which is here performed, and from which all these creatures were produced,-- and so they are even now produced after this one. Thus he places him (the Sacrificer) in the very middle of that Pragâpati, and quickens him in the middle: this is why that ceremony is performed between two offerings. Having called for the Sraushat. he says, 'Urge for Agni Svishtakrit!' and offers as the Vashat is pronounced.