Shatapatha Brahmana 8.7.2.14

8.7.2.14

sa eṣa prāṇa eva yallokampṛṇā | tayā sarvamātmānam pracādayati sarvasmistadātmanprāṇaṃ dadhāti tadyaddhāsyaiṣāṅgaṃ nābhiprāpnuyātprāṇo hāsya tadaṅgaṃ nābhiprāpnuyādyadu vai prāṇo 'ṅgaṃ nābhiprāpnoti śuṣyati vā vai tanmlāyati vā tasmādenaṃ sarvamevaitayā pracādayet

The Lokamprinâ, doubtless, is the same as the vital air; he therewith fills up the whole body (of the altar): he thus puts vital air into the whole body. If he were not to reach any member thereof, then the vital air would not reach that member of him (Agni); and whatever member the vital air does not reach, that, assuredly, either dries up or withers away: let him therefore fill up therewith the whole of it.