One verse

Srimad Bhagavatam 4.8.75

4.8.75

चतुर्थमपि वै मासं द्वादशे द्वादशेऽहनि । वायुभक्षो जितश्वासो ध्यायन्देवमधारयत् ॥ ७५ ॥

caturtham api vai masam dvadase dvadase ’hani vayu-bhakso jita-svaso dhyayan devam adharayat

caturtham
fourth
api
also
vai
in that way
masam
the month
dvadase dvadase
on the twelfth
ahani
day
vayu
air
bhaksah
eating
jita-svasah
controlling the breathing process
dhyayan
meditating
devam
the Supreme Lord
adharayat
worshiped.

In the fourth month Dhruva Maharaja became a complete master of the breathing exercise, and thus he inhaled air only every twelfth day. In this way he became completely fixed in his position and worshiped the Supreme Personality of Godhead.