Chandogya Upanishad 7.9

7.9.1

annaṃ vāva balād bhūyaḥ \
tasmād yady api daśa rātrīr nāśnīyāt \
yady u ha jīvet \
athavādraṣṭāśrotāmantāboddhākartāvijñātā bhavati \
athānnasyāye draṣṭā bhavati śrotā bhavati mantā bhavati boddhā bhavati kartā bhavati vijñātā bhavati \
annam upāssveti \\709.1\

1. ‘Food (anna), assuredly, is more than Strength. Therefore, if one should not eat for ten days, even though he might

live, yet verily he becomes a non-seer, a non-hearer, a non-thinker, a non-perceiver, a non-doer, a non-understander. But on the entrance of food he becomes a seer, he becomes a hearer, he becomes a thinker, he becomes a perceiver, he becomes a doer, he becomes an understander. Reverence Food.

7.9.2

sa yo 'nnaṃ brahmety upāste \
annavato vai sa lokān pānavato 'bhisidhyati \
yāvad annasya gataṃ tatrāsya yathākāmacāro bhavati yo 'nnaṃ brahmety upāste \
asti bhagavo 'nnād bhūya iti \
annād vāva bhūyo 'stīti \
tan me bhagavān bravītv iti \\709.2\

2. He who reverences Food as Brahma—he, verily, attains the worlds of Food and Drink. As far as Food goes, so far he has unlimited freedom, he who reverences Food as Brahma.’ ‘Is there, Sir, more than Food?’ ‘There is, assuredly, more than Food.’ ‘Do you, Sir, tell me it.’