Śatapatha Brāhmaṇa ("of a hundred paths") 3.6.2.25

3.6.2.25

sa yadagnau juhoti | taddeveṣu juhoti tasmāddevāḥ santyatha yatsadasi bhakṣayanti tanmanuṣyeṣu juhoti tasmānmanuṣyāḥ santyatha yaddhavirdhānayornārāśaṃsāḥ sīdanti tatpitṛṣu juhoti tasmātpitaraḥ santi

Now what he offers in the fire, that he offers unto the gods, thereby the gods exist; and what (Soma) is consumed in the Sadas, that he offers unto men, thereby men exist; and in that the Nârâsamsa cups of Soma) stand with the Soma-carts, thereby he offers unto the Fathers, thereby the Fathers exist.