Chandogya Upanishad 4.8.3

4.8.3

brahmaṇaḥ somya te pādaṃ bravāṇi iti \
bravītu me bhagavān iti \
tasmai hovāca \
prāṇaḥ kalā \
cakṣuḥ kalā \
śrotraṃ kalā \
manaḥ kalā \
eṣa vai somya catuṣkalaḥ pādo brahmaṇa āyatanavān nāma \\408.3\

3. ‘Let me tell you, my dear, a quarter of Brahma.’ ‘Tell me, Sir.’ To him it then said: ‘One sixteenth is breath. One sixteenth is the eye. One sixteenth is the ear. One sixteenth is mind. This, verily, my dear, is the quarter of Brahma, consisting of four sixteenths, named Possessing-a-support. 4. He who, knowing it thus, reverences a quarter of Brahma, consisting of four sixteenths, as Possessing-a-support, comes to possess a support in this world. Then he wins worlds possessing a support who, knowing it thus, reverences a quarter of Brahma, consisting of four sixteenths, as Possessing-a-support.’