Kauṣītaki (Śāṅkhāyana) Brāhmaṇa 4.9.9

4.9.9

indrāgnī vai devānām mukham /

Indra and Agni, and Indra and Agni are the beginning of the gods, verily thus at the beginning he delights the gods. In that there is a pap for the All-gods, and the All-gods are all the gods, verily (it serves) to delight all the gods. In that there is (a cake) on one potsherd for sky and earth, (it is because) sky and earth are the preparers of the harvest, and earth is a support, and by the flooding yonder (sky) co-operates. In that he sacrifices to these deities, (it is because he thinks) 'By these deities shall I eat food made calm.' In that he gives an ox of the first birth, it is because this is a first ceremony. If he is wearied of this (sacrifice), he should offer the oblation of the full or the new moon, with the new (plants) to obtain both. Or again he may employ the oblations at the full moon or the new moon (sacrifice) to secure the presence of the deities. Or again he may offer in the morning and in the evening the Agnihotra with barley gruel of the new (plants), to obtain both. Or again having cooked milk in a pot on the Gārhapatya he should make an offering of the new (plants) in the Āhavanīya to the gods of the Āgrayaṇa, with Sviṣṭakṛt for a fourth (saying) 'To N.N. hail. To N.N. hail!' to secure the presence of the deities. Or again having made the Agnihotra cow to eat the new (plants), he should offer in the morning and in the evening the Agnihotra with its milk, to obtain both. These are so many possibilities; he may offer with whichever he may desire, but the established rule is that of three oblations. Three are these worlds; verily thus he obtains these worlds.