Aitareyabrahmana 2.36

2.36

devāsurā vā eṣu lokeṣu samayatanta.
te vai devāḥ sada evāyatanam akurvata, tān sadaso 'jayaṃs.
ta āgnīdhraṃ samprāpadyanta, te tato na parājayanta.
tasmād āgnīdhra upavasanti na sadasy, āgnīdhre hy adhārayanta.
yad āgnīdhre 'dhārayanta tad āgnīdhrasyāgnīdhratvaṃ
teṣāṃ vai devānām asurāḥ sadasyān agnīn nirvāpayāṃ cakrus.
te devā āgnīdhrād eva sadasyān agnīn viharanta,
tair asurarakṣāṃsy apāghnata.
tathaivaitad yajamānā āgnīdhrād eva sadasyān agnīn viharanty,
asurarakṣāṃsy eva tad apaghnate
te vai prātar ājyair evājayanta āyan.
yad ājyair evājayanta āyaṃs tad ājyānām ājyatvaṃ
tāsāṃ vai hotrāṇām āyatīnām ājayantīnām achāvākīyāhīyata.
tasyām Indrāgnī adhyāstām.
Indrāgnī vai devānām ojiṣṭhau baliṣṭhau sahiṣṭhau sattamau
pārayiṣṇutamau. tasmād aindrāgnam achāvākaḥ prātaḥsavane
śaṃsatīndragnī hi tasyām adhyāstāṃ
tasmād u purastād anye hotrakāḥ sadaḥ prasarpanti paścāchāvākaḥ,
paśceva hi hīno 'nusaṃjigamiṣati
tasmād yo brāhmaṇo bahvṛco vīryavān syāt so 'syāchāvākīyāṃ kuryāt,
tenaiva sāhīnā bhavati

ii. 36 (x. 4). The gods and the Asuras fought over these worlds; the gods made the Sadas their refuge; they conquered them from the Sadas; they went to the Agnīdh’s altar; they were not conquered thence. Therefore they spend the fast day at the Agnīdh’s altar, not in the Sadas, for they were supported at the Agnīdh’s altar; in that they were supported at the Agnīdh’s altar that is why the Agnīdh’s altar has its name. The Asuras made a scattering of the fires of those gods in the Sadas; the gods drew off the fires in the Sadas from the Agnīdh’s altar; with them they repelled the Asuras and the Rakṣases; verily thus also the sacrificers draw off the fires in the Sadas from the Agnīdh’s altar; verily thus they repel the Asuras and the Rakṣases. In the morning they kept conquering by the Ājyas; in that they kept conquering (ājayanta āyan) by the Ājyas that is why the Ājyas have their name. Of the Hotṛ offices which continued conquering, that of the Achāvāka was left out; in it Indra and Agni took their place; Indra and Agni are the most forcible, mighty, strong, rich, and effective of the gods; therefore (a hymn) to Indra and Agni the Achāvāka recites at the morning pressing, for Indra and Agni took their place in it. Therefore the other Hotrakas creep to the Sadas in front, the Achāvāka behind, for being left behind as it were he is anxious to follow after. Therefore a Brahman, skilled in the Ṛc verses and strong, should perform the Achāvāka’s part; thereby it does not become neglected.