Śatapatha Brāhmaṇa ("of a hundred paths") 9.3.1.24

9.3.1.24

atha yāḥ sapta pratīcyaḥ sravanti | so 'raṇye 'nūcyaḥ sa saptakapālo bhavati sapta hi tā yāḥ pratīcyaḥ sravanti so 'syaiṣo 'vāṅ prāṇa etasya prajāpateḥ so 'raṇye 'nūcyo bhavanti tira iva tadyadaraṇyaṃ tira ivaṃ tadyadavāṅ prāṇastasmādya etāsāṃ nadīnām pibanti ripratarāḥ śapanatarā āhanasyavāditarā bhavanti tadyadyadetadāhedam mārutā iti tadasmā annaṃ kṛtvāpidadhāti tenainam prīṇāti

And the Aranyeऽnûkya is the seven (rivers) which flow westwards; it is one of seven potsherds, for there are seven of those (rivers) which flow westwards. It is that downward vital air of his. That Aranyeऽnûkya belongs to this Pragâpati; for the forest (aranya) is, as it were, concealed, and concealed, as it were, is that downward vital air; whence those who drink of these (downward flowing) rivers become most vile, most blasphemous, most lascivious in their speech. Whenever he here speaks of them as belonging to the Maruts, he makes them food for him (Agni) and offers it to him, and gratifies him thereby.