Śatapatha Brāhmaṇa ("of a hundred paths") 3.5.2.9

3.5.2.9

sa yaddhāryamāṇe 'gnau | uttaravediṃ vyāghārayati yadevaināmado devā abruvanpūrvāṃ tvāgnerāhutiḥ prāpsyatīti tadevaināmetatpūrvāmagnerāhutiḥ prāpnoti yadveṣā devānabravīdyāṃ mayā kāṃ cāśiṣamāśāsiṣyadhve sā vaḥ sarvā samardhiṣyata iti tāmenayātrartvijo yajamānāyāśiṣamāśāsate sāsmai sarvā samṛdhyate

Now as to why he pours ghee on the high altar, while the fire is held (over it). Because the gods said to her on that occasion, 'The offering shall reach thee before Agni,' therefore the offering now does reach her before (it reaches) Agni. And because she said to the gods, 'Whatsoever blessing ye will invoke through me, all that shall be accomplished unto you!' therefore the priests now invoke through her that blessing upon the sacrificer, and it is fully accomplished unto him.