Śatapatha Brāhmaṇa ("of a hundred paths") 2.2.3.24

2.2.3.24

tata etattvaṣṭā punarādheyaṃ dadarśa | tadādadhe tenāgneḥ priyaṃ dhāmopajagāma so 'smā ubhayāni rūpāṇi pratiniḥsasarja yāni ca grāmyāṇi yāni cāraṇyāni tasmādāhustvāṣṭrāṇi vai rūpāṇīti tvaṣṭurhyeva sarvaṃ rūpamupa ha tvevānyāḥ prajā yāvatso yāvatsa iva tiṣṭhante

He then says, as to the chief offering (havis), 'Pronounce the invitatory prayer to Agni!' 'Pronounce the offering-prayer to Agni!' 'Pronounce the invitatory prayer to Agni Svishtakrit (the maker of good offerings)!' 'Pronounce the offering-prayer to Agni Svishtakrit!' Then where (otherwise) he would say, 'Pronounce the offering-prayer to the gods!' he now says, 'Pronounce the offering-prayer to the Agnis!'