Shatapatha Brahmana 10.3.1.8

10.3.1.8

atha yo'yamavāṅ prāṇaḥ eṣa jagatīti tadya evaitasya prāṇasya mahimā yadvīryaṃ tadetatsahasrametasyaivaitatprāṇasya vīryaṃ yaddhyasya cinvata eṣa pralṇa ā6ubhyettata evaiṣo'gnirna cīyetaitenaivāsya rūpeṇa sahasrameṣa jagatīḥ saṃcito bhavati

'And the Gagatî is that downward breathing,'--thus, whatever power, whatever vigour there is in that breathing, that is this one thousand; and to that breathing, indeed, this vigour belongs, for were that breathing of him who builds it to become disordered, this fire-altar, assuredly, would not be built: by this its form that (altar) becomes built (so as to include) a thousand Gagatîs.