This is a practice in which the flow of the breath alternates between nostrils:
in Left Nostril (LN), out RN, in RN, out LN, and so on.
There is no retention.
This practice helps to balance the rhythms of the expressive and receptive sides, and is useful as a preparation for further practice.
To the All-Pervading life in space.
The breath as a current of light, drawn to the third eye on the inhalation and sent out from there on the exhalation.