Śatapatha Brāhmaṇa ("of a hundred paths") 7.5.2.3

7.5.2.3

yadveva paśuśīrṣāṇyupadadhāti | yā vai tāḥ śriya etāni tāni paśuśīrṣāṇyatha yāni tāni kusindhānyetāstāḥ pañca citayastadyāstāḥ pañca citaya ime te lokāstadye ta ime lokā eṣā sokhā tadyadukhāyām paśuśīrṣāṇyupadadhātyetaireva tacīrṣabhiretāni kusindhāni saṃdadhāti

And, again, why he puts the heads of the victims therein;--what (animal) perfections (srî) there were, they are these victims’ heads; and what rumps there were, they are those five layers (of the altar). Now those five layers are these worlds, and these worlds are this very fire-pan: thus, when he puts the heads of the victims in the fire-pan, he thereby unites those rumps with those heads.