Breath is life. Meditating upon its presence is meditating upon our lives. It is the now, the present as it is. We can apply the skill in almost all the things we do daily. As soon as we bring our attention to the breath, the great power of observation comes to us naturally.
Once the nada is heard, slowly pierce through it until a softer sound appears. Focus on this new sound. Then go past the new sound and another one shall emerge. The nada is inside the mind only and the sound is to be heard in the mind only. We cannot create these sounds, they are already there. We have to attune our minds for the nada to manifest.
Finally, we must learn how to breathe through the Union of the Soma and Kundalini. There are actually two places where we could do this practice. One is inside the heart and the other one occurs through the third eye. Feel the inspiring of the breath open the space of the heart and allow it to melt and relax through each exhalation. When we breathe through the heart, the mind and breath are calm and balanced.
The mind emerges the energy of the soul. This spiritual force is the most healing, for ourselves and others.
When the Kundalini is awakened properly, it could be directed to enter the Sushumna nadi where the chakras of the subtle body exist. She irrigates her pathway as she makes her way up, loosening the knots of ignorance known as the granthis, which in turn illuminates the soul.
The euphoria attached to Samadhi is beautiful. It is many times addicting too. The student knows his limitations so he could easily get out. Once or twice in this lifetime is enough. To chase it could lead to a painful downfall. He needs to come back so he could share this wondrous spiritual journey.