Gobhilagrihyasutra 1.4.25

1.4.25

yasya tv eṣām agrataḥ sidhyed, niyuktam agnau kṛtvā 'graṃ brāhmaṇāya dattvā bhuñjīta;

However (of the persons belonging to the family) he whose food becomes ready before (that of the householder), (that person) should offer the prescribed portion in the fire, and give to a Brâhmana his share (of the food), and then should eat himself.