Shatapatha Brahmana 6.8.1.15

6.8.1.15

athātaḥ sampadeva | samidham prathamenādadhātyudyacatyekena prayātyekenākṣamekenānumantrayate samidhameva pañaemenādadhāti tatpañca pañcacitiko 'gniḥ pañca 'rtavaḥ saṃvatsaraḥ saṃvatsaro 'gniryāvānagniryāvatyasya mātrā tāvattadbhavati

Now, then, the (symbolic) correspondence,--with the first (formula) he puts on a kindling-stick, with one he lifts him up, with one he starts, with one he addresses the axle, with the fifth he puts on a kindling-stick, that makes five,--of five layers consists the fire-altar, five seasons are a year, and the year is Agni: as great as Agni is, as great as is his measure, so great does this become.