Śatapatha Brāhmaṇa ("of a hundred paths") 3.8.3.8

3.8.3.8

sa hṛdayamevāgre 'bhighārayati | ātmā vai mano hṛdayam prāṇaḥ pṛṣadājyamātmanyevaitanmanasi prāṇaṃ dadhāti tathaitajjīvameva devānāṃ havirbhavatyamṛtamamṛtānām

The heart he bastes (with clotted ghee) first of all; for the heart is the self (soul), the mind; and the clotted ghee is the breath; he thus puts the breath into its (the victim's) self, into its mind; and thus it verily becomes the living food of the gods, and immortal for the immortals.