Śatapatha Brāhmaṇa ("of a hundred paths") 10.5.4.7

10.5.4.7

candāṃsi ha tvevaiṣo'gniścitaḥ tāni vā etāni sapta candāṃsi caturuttarāṇi tricāni teṣāṃ sapta ca śatāni viṃśatiścākṣarāṇyadhi ṣaṭtriṃśattato yāni sapta ca śatāni viṃśatiśceṣṭakā eva tāḥ ṣaṣṭiśca trīṇi ca śatāni pariśritaḥ ṣaṣṭiśca trīṇi ca śatāni yajuṣmatyo'tha yānyadhi ṣaṭtriṃśatsa trayodaśo māsaḥ sa ātmā triṃśadātmā pratiṣṭhā dve prāṇā dve śira eva ṣaṭtriṃśyau tadyatte dve bhavato dvyakṣaraṃ hi śiraḥ

But, indeed, that Fire-altar also is the Metres; for there are seven of these metres, increasing by four syllables; and the triplets of these make seven hundred and twenty syllables, and thirty-six in addition thereto. Now what seven hundred and twenty bricks there are of these, they are the three hundred and sixty enclosing-stones and the three hundred and sixty Yagushmatîs; and what thirty-six there are in addition, they are the thirteenth month, and the body (of this altar),--the trunk (consisting of) thirty, the feet of two, the vital airs of two, and the head itself being the (thirty-fifth and) thirty-sixth; and as to there being two of these, it is because 'siras' consists of two syllables.