Śatapatha Brāhmaṇa ("of a hundred paths") 2.2.1.14

2.2.1.14

sa etāstisrastanūreṣu lokeṣu vinyadhatta | yadasya pavamānaṃ rūpamāsīttadasyām pṛthivyāṃ nyadhattātha yatpāvakaṃ tadantarikṣe 'tha yacuci taddivi tadvā ṛṣayaḥ pratibubudhire ya u tarhyṛṣaya āsurasarveṇa vai na ātmanāgnirabhyupāvṛtaditi tasmā etāni havīṃṣi niravapan

He then laid down in these (three) worlds those three bodies of his. That 'blowing (pavamâna)' form of his he laid down on this earth, that 'purifying (pâvaka)' one in the ether, and that 'bright (suki)' one in the sky. Now the Rishis then existing became aware of this: 'Agni has not come to us with his whole body,' they said. They then prepared those oblations for him.