Śatapatha Brāhmaṇa ("of a hundred paths") 2.3.1.11

2.3.1.11

sa yatsāyamastamite juhoti | asya rasasya jīvanasya devebhyo juhavāni yadeṣāmidaṃ sadupajīvāma iti sa yattato rātryāśnāti hutociṣṭhameva tanniravattabalyaśnāti hutociṣṭasya hyevāgnihotraṃ juhvadaśitā

Now when he offers in the evening after sunset, he does so thinking, 'I will offer to the gods of this life-giving juice: we subsist on this which belongs to them.' And when he afterwards takes his evening meal, he eats what remains of the offering, and whereof oblative portions (bali) have been distributed all round; for he who performs the Agnihotra eats only what remains of the offering.