Aitareyabrahmana 3.39: adhyāya 14, khaṇḍaḥ 1-6

3.39

devā vā asurair yuddham upaprāyan vijayāya, tān Agnir nānvakāmayataituṃ.
taṃ devā abruvann: api tvam ehy, asmākaṃ vai tvam eko 'sīti.
sa nāstuto 'nveṣyāmīty abravīt, stuta nu meti.
taṃ te samutkramyopanivṛtyāstuvaṃs, tān stuto 'nuprait
sa triḥśreṇir bhūtvā tryanīko 'surān yuddham upaprāyad vijayāya.
triḥśreṇir iti chandāṃsy eva śreṇīr akuruta,
tryanīka iti savanāny evānīkāni.
tān asambhāvyam parābhāvayat.
tato vai devā abhavan, parāsurā
bhavaty ātmanā, parāsya dviṣan pāpmā bhrātṛvyo bhavati, ya evaṃ veda
sā vā eṣā gāyatry eva yad agniṣṭomaś.
caturviṃśatyakṣarā vai gāyatrī, caturviṃśatir agniṣṭomasya stutaśastrāṇi
tad vai yad idam āhuḥ: sudhāyāṃ ha vai vāji suhito dadhātīti.
gāyatrī vai tan.
na ha vai gāyatrī kṣamā ramata,
ūrdhvā ha vā eṣā yajamānam ādāya svār etity.
agniṣṭomo vai tan. na ha vā agniṣṭomaḥ kṣamā ramata,
ūrdhvo ha vā eṣa yajamānam ādāya svar eti
sa vā eṣa saṃvatsara eva yad agniṣṭomaś.
caturviṃśatyardhamāso vai saṃvatsaraś,
caturviṃśatir agniṣṭomasya stutaśastrāṇi
taṃ yathā samudraṃ srotyā evaṃ sarve yajñakratavo 'piyanti

iii. 39 (xiv. 1). The gods undertook battle with the Asuras, for conquest; them Agni was not willing to accompany. To him the gods said

'Do thou come too; thou art one of us.' He replied 'I shall not follow you if I am not sung to; sing now to me.' They, having risen, and having returned, praised him; them praised he followed. Becoming in three rows, he went to battle for conquest with the Asuras in three columns; 'in three rows' (he says); verily he made the metres rows; 'in three columns' (he says); the pressings (he made) the columns. Them he defeated invincibly; then indeed the gods prospered, the Asuras were defeated. He prospers himself, the evil rival who hates him is defeated, who knows thus. The Agniṣṭoma is the Gāyatrī; the Gāyatrī has twenty-four syllables; there are twenty-four Stotras and Çastras in the Agniṣṭoma. This is why they say 'A horse well loaded gives (its rider) comfort. This is the Gāyatrī; the Gāyatrī is not content with the earth; taking with it the sacrificer it goes aloft to the sky.' This is the Agniṣṭoma; the Agniṣṭoma is not content with the earth; taking with it the sacrificer it goes aloft to the sky. The Agniṣṭoma is the year; the year has twenty-four half-months; there are twenty-four Stotras and Çastras in the Agniṣṭoma. As in the ocean all streams, so in it all the sacrificial rites are resolved.