AITAREYA UPANISHAD · 1.3.10

तदपानेनाजिघृक्षत् तदावयत् सैषोऽन्नस्य ग्रहो यद्वायुरन्नायुर्वा एष यद्वायुः ॥ १० ॥

tadapānenājighṛkṣat tadāvayat saiṣo’nnasya graho yadvāyurannāyurvā eṣa yadvāyuḥ ॥ 10 ॥

By the Apana He would have seized it, and it was seized. Lo this is the seizer of food which is also Breath of the Life, and therefore all that is Breath hath its life in food.