Śatapatha Brāhmaṇa ("of a hundred paths") 1.4.2.16

1.4.2.16

āvaha devānyajamānāyeti | tadasmai yajñāya devānāvoḍhavā āhāgnimagna āvaheti tadāgneyāyājyabhāgāyāgnimāvoḍhvā āha somamāvaheti tatsaumyāyājyabhāgāya somamāvoḍhavā āhāgnimāvaheti tadya eṣa ubhayatrācyuta āgneyaḥ puroḍāśo bhavati tasmā agnimāvoḍhavā āha

'Bring hither the gods for the sacrificer!' this he says in order that he (Agni) may bring the gods to this sacrifice.--'Bring Agni hither, O Agni!' this he says in order that he may bring Agni to the butter-portion intended for Agni.--'Bring Soma hither!' this he says in order that he may bring Soma to the butter-portion intended for Soma. 'Bring Agni hither!' this he says in order that he (Agni) may bring Agni hither to that indispensable cake which is offered to Agni on both occasions (at the new- and the full-moon sacrifices).