Jāgaraṇa means to remain awake the entire night of Shivaratri while spending time in worship or other spiritual activities. Jāgarana not only mean staying awake, it also means being alert and controlling the 10 senses i.e. 5 organs of perception as well as the 5 organs of action! It means to not go into dream or deep sleep states. It symbolizes a state of being endlessly awake. Being endlessly awake always is liberation (moksha)! This is Self-knowledge (atma jnana)!
How do we reach this state of being eternally awake? To reach there, first of all during this present waking state, japa, pujas, homas and traditional religious practices should be conducted. It is a known fact that the activities conducted in dream state are of no use. Even good activities done in a dream are useless when we awaken.
Only those activities performed during the waking state are our real experiences. If the Self (atma) truly wants to obtain the real experience then it has to be attempted only during the waking state. That is why Shiva yogi has initiated his devotees to ‘keep awake’ tonight.
Only during awaking state, Lingodbhava (emergence of the linga) can take place. Lingodbhava means that this Atma, that is travelling again and again, becomes stable, without any movement. Such knowledge can be gained only through devotion. The star Mrigashira can be seen tonight in the sky. It signifies devotion. You should learn this devotion. This morning you can sleep if you wish. But, after remaining awake all night, do not sleep tomorrow morning. If you sleep between sunrise and sunset tomorrow, then all the spiritual or good-disciplines of today will result in a waste. The demons will steal the results of this good austerities from you. However, sick people are exempted from this rule.
-Glimpses of Bhaktimala