Śāṅkhāyana (Kauṣītaki) Āraṇyaka 2.10

2.10

ŚĀ 2,10
indraḥ suteṣu someṣv ityetayauṣṇihīm aśītiṃ pratipadyate vide vṛdhasya dakṣaso mahān hi ṣa iti vṛdhavatyā mahadvatyā | vṛdhavan mahadvat | mahadvad dhyetad ahaḥ | tā vā etā aśītayaḥ saṃśastāḥ saptaviṃśatiśatānyṛcāṃ saṃpadyante | sapta vai viṃśati śatāni saṃvatsarasyāhorātrāṇāṃ tad aśītibhiḥ saṃvatsarasyāhorātrāṇyāpnoti | sāmanidhanair haike gāyatrīr uṣṇihaḥ saṃpādayanti | caturakṣarāṇyu haike punar ādadate | bārhatyā aśītyā aśītiṃ caturakṣarāṇyuddharati kākubhebhyaḥ pragāthebhyaś caturviṃśatiṃ caturakṣarāṇi tāni catuḥśataṃ caturakṣarāṇi catuḥśate gāyatrīṣūpadadhāti | tathā tā gāyatrīr uṣṇihaḥ saṃpadyante | nādriyeta | atraiva saṃpannam | indrāya sāma gāyateti | tad yad etad antataḥ śaṃsati saṃsiddhābhir uṣṇigbhir vaśaṃ samārohāṇīti ||

ŚĀ 2.10
With [the verse], 'Indra, when the soma is pressed,' he commences the Auṣṇiha eighty, [with the words], 'I know him of increased strength; for great is he,' which contains [a word meaning] 'increase' and [a word meaning] 'great.' It contains 'increase' and contains 'great.' For great indeed is this day. When recited, these eighties amount to seven hundred and twenty verses. Seven hundred and twenty indeed are the days and nights of a year; thus by means of the eighties he obtains the days and nights of a year. Some indeed make up [the verses into] Uṣṇihs from Gāyatrīs by means of the sāman cadences. Some also take back four-syllable [units]: from the Bārhata eighty, he takes out eighty four-syllable [units]; from the Kākubha Pragāthas, twenty-four four-syllable [units]; these are one hundred and four four-syllable [units]; he places them onto the one hundred and four Gāyatrīs. In this way those Gāyatrīs become Uṣṇihs. One should not heed this. Right here it is accomplished [with]: 'Sing a chant to Indra.' Now, as to why he recites this at the end: [he thinks,] 'Let me ascend to the Vaśa with fully completed Uṣṇih [verses].'