Brihadaranyaka Upanishad 3.68

तदाहुर्यद्अयमेकः इव पवत अथ कथमध्यर्ध इति | यदस्मिन्निदं सर्वमध्यार्ध्नोत्तेनाध्यर्ध इति | कतम एको देव इति | प्राण इति | स ब्रह्म | त्यदित्याचक्षते ॥

tad ahur yad ayam ekah iva pavata atha katham adhyardha iti | yadasminn idam sarvam adhyaardhnot tena adhyardha iti | katama eko deva iti | prana iti | sa brahma | tyad ity achakshate ||

'They say: since the wind blows as one, how is he one and a half? Because in him all this grows to greatness (adhyardhnot), therefore he is one and a half.' 'Which is the one God?' 'The prana (breath, life-force). He is Brahman. They call him Tyat (That).'

'किन्तु वायु तो एक के समान बहता है — फिर डेढ़ कैसे?' 'क्योंकि उसी में यह सब बढ़ता है (अध्यर्ध्नोत्), इसलिए वह 'अध्यर्ध' (डेढ़) है।' 'वह एक देव कौन है?' 'प्राण। वही ब्रह्म है। उसे 'त्यत्' (वह) कहा जाता है।'