Chandogya Upanishad 4.10.3

4.10.3

sa ha vyādhinā anaśituṃ dadhre \
tam ācāryajāyā uvāca brahmacārinn aśāna \
kiṃ nu na aśnāsi iti \
sa ha uvāca bahava ime asmin puruṣe kāmā nānātyāyāḥ \
vyādhībhīḥ pratipūrṇo 'smi \
na as/iṣyāmi iti \\410.3\

3. Then, on account of sickness, he [i. e. Upakosala] took to not eating. The teacher’s wife said to him: ‘Student of sacred knowledge, eat. Why, pray, do you not eat?’ Then he said: ‘Many and various are the desires here in this man. I am filled up with sicknesses. I will not eat.’