Śatapatha Brāhmaṇa ("of a hundred paths") 1.1.1.9

1.1.1.9

tadu hovāca yājñavalkyaḥ | yadi nāśnāti pitṛdevatyo bhavati yadyu aśnāti devānatyaśnātīti sa yadevāśitamanaśitaṃ tadaśnīyāditi yasya vai havirna gṛhṇanti tadaśitamanaśitaṃ sa yadaśnāti tenāpitṛdevatyo bhavati yadyu tadaśnāti yasya havirna gṛhṇanti teno devānnātyaśnāti

Yâgñavalkya, on the other hand, said: 'If he does not eat, he thereby becomes a sacrificer to the Manes; and if he does eat, he eats before the gods have eaten: let him therefore eat what, when eaten, counts as not eaten.' For that of which no offering is made, even though it is eaten, is considered as not eaten. When he therefore eats, he does not become a sacrificer to the Manes; and by eating of that of which no offering is made, he does not eat before the gods have eaten.