Gopathabrahmana 1.4.15

1.4.15

atha yac caturviṃśam ahar upetyānupetya viṣuvantaṃ mahāvratam upeyāt katham anāgūrtyai bhavatīti
yam evāmuṃ purastād viṣuvato 'tirātram upayanti teneti brūyāt_
abhiplavāt pṛṣṭhyo nirmitaḥ
pṛṣṭhyād abhijit_
abhijitaḥ svarasāmānaḥ
svarasāmabhyo viṣuvān [ed. viṣavān]
viṣuvataḥ svarasamānaḥ
svarasāmabhyo viśvajit_
viśvajitaḥ pṛṣṭhyābhiplavau
pṛṣṭhyābhiplavābhyāṃ gavāyuṣī
gavāyurbhyāṃ daśarātraḥ_
atha ha devebhyo mahāvrataṃ na tasthe katham ūrdhvai stomair viṣuvantam upāgātāvṛttair mām iti
te devā ihasāmivāsur
upa taṃ yajñakratuṃ jānīmo ca ūrdhvastomo yenaitad ahar avāpnuyāmeti
tata etaṃ dvādaśarātram ūrdhvastomaṃ dadṛśus
tam āharan_
tenāyajanta
tata ebhyo 'tiṣṭhan_
tiṣṭhati hāsmai mahāvratam_
pratitiṣṭhati
pratitiṣṭhati prajayā paśubhir ya evaṃ veda || 15 ||