Chandogya Upanishad 6.6

dadhnaḥ somya mathyamānasya yo 'ṇimā sa ūrdhvaḥ samudīṣati tat sarpir bhavati

'That which is the subtile portion of curds, when churned, rises upwards, and becomes butter.

evam eva khalu somyānnasyāśyamānasya yo 'ṇimā sa ūrdhvaḥ samudīṣati tan mano bhavati

'In the same manner, my child, the subtile portion of earth (food), when eaten, rises upwards, and becomes mind.

apāṃ somya pīyamānānāṃ yo 'ṇimā sa ūrdhvaḥ samudīṣati sā prāṇo bhavati

'That which is the subtile portion of water, when drunk, rises upwards, and becomes breath.

tejasaḥ somyāśyamānasya yo 'ṇimā sa ūrdhvaḥ samudīṣati sā vāg bhavati

'That which is the subtile portion of fire, when consumed, rises upwards, and becomes speech.

annamayaṃ hi somya manaḥ āpomayaḥ prāṇaḥ tejomayī vāg iti bhūya eva mā bhagavān vijñāpayatv iti tathā somyeti hovāca

'For mind, my child, comes of earth, breath of water, speech of fire.' 'Please, Sir, inform me still more,' said the son. 'Be it so, my child,' the father replied.