I am that.
This mantra helps us to move beyond the limits of our personal existence and recognize ourselves are part of all things. It is a simple mantra that can become a very profound mantra and meditation practice. Below is a meditation technique using the mantra.
Find a comfortable seat for meditation (you can use a bolster or blanket or can also sit in a chair with the spine erect). Close your eyes and find the breath. Start to connect with the length of the spine and feel the breath move up the spine on the inhale and down the spine on the exhale.
As the breath starts to lengthen and deepen start to chant “So” silently to yourself as you inhale and “Hum” as you exhale. Feel the breath move in waves through the body. Feel the entire length of the inhale take you through the sound of “So” and the entire length of your exhale take you through “Hum.” Let the mind become completely absorbed in the mantra and in the breath. If thought does arise, return to your inhale and exhale and begin the mantra again.
It can be helpful to set a timer for 10, 20, or 30 minutes when you first begin this practice. Then as you grow more comfortable you will find the mind will be less likely to wander off during the practice and you will find less need for the timer.
To close the practice, complete the exhale of “Hum” and return to a normal breath and quiet mind. Draw the hands to the heart center in anjali mudra (prayer pose). You can close with a mantra, the sound of om or perhaps a prayer or intention.