Sri M said...

The Northern (upward) movement of the Prana is when it finally goes through the seven wheels or the seven psychic centres along the sushumna nadi until it reaches the highest heaven in the Sahasraara chakra, full of water. The water here means apastatva, the tatva of liquidity, of movement identified with the moon or the Soma. Having reached there, the Rishi is never unborn and he lives identified with the omniscient.