Śatapatha Brāhmaṇa ("of a hundred paths") 9.2.3.45

9.2.3.45

sapta sapteti | saptacitiko 'gniḥ sapta 'rtavaḥ saṃvatsaraḥ saṃvatsaro 'gniryāvānagniryāvatyasya mātrā tāvataivainametatprīṇāti tisra āhutīrjuhoti trivṛdagniryāvānagniryāvatyasya mātrā tāvataivainametadannena prīṇāti tisraḥ samidha ādadhāti tatṣaṭ tasyokto bandhuḥ

'Seven' he says each time,--of seven layers the fire-altar consists, and of seven seasons the year, and Agni is the year: as great as Agni is, as great as is his measure, with so much he thus gratifies him. Three oblations he offers,--threefold is Agni: as great as Agni is, as great as is his measure, with so much food he thus gratifies him. Three logs he puts on,--that makes six: the significance of this has been explained.