Śatapatha Brāhmaṇa ("of a hundred paths") 13.6.2.11

13.6.2.11

ājyena juhoti tejo vā ājyam tejasaivāsmiṃstattejo dadhātyājyena juhotyetadvai devānām priyaṃ dhāma yadājyam priyeṇaivaināndhāmnā samardhayati ta enaṃ samṛddhāḥ samardhayanti sarvaiḥ kāmaiḥ

He makes offering with ghee, for ghee is fiery mettle: by means of fiery mettle he thus endows him (the Sacrificer) with fiery mettle. He makes offering with ghee, for that--to wit, ghee--is the dear resource of the gods: he thus supplies them with their dear resource, and, thus supplied, they supply him with all his objects of desire.