There are subtle tubes that carry Prana. The Moon moves in the Ida and the Sun in the Pingala. Ida is cooling. Pingala is heating. Ida flows through the left nostril and the Pingala through the right nostril. The breath flows through the right nostril for one hour and then through the left nostril for one hour. Man is busily engaged in worldly activities, when the breath flows through Ida and Pingala. When Sushumna operates, he becomes dead to the world, and enters into Samadhi.
A Yogi tries his level best to make the Prana run in the Sushumna Nadi, which is known as the central Brahman Nadi also. On the left of Sushumna is situated Ida and on the right is Pingala. The moon is of the nature of Tamas and the sun is that of the Rajas. The poison share is of the sun and the nectar is of the moon. Ida and Pingala indicate time. Sushumna is the consumer of time."
