The Upanishad Mantra Meditation is one of my favourites in Letters from the Yoga Masters on page 165. It includes four mantras that are intended to help awaken our consciousness to the spirit within. Along with the mantras we visualize the flow of prana. I have slightly modified this version of the meditation for flow. To hear the mantras in this meditation, go to sanskrit, chants and mantras and scroll to the last mantra on the list.
Sit in a meditative posture. Breathing is free. Gradually the mind is absorbed in experiencing the inhalation and exhalation (pranas). As a consequence of concentration, the breath becomes slow.
For several minutes experience the cool air entering inside the upper nostrils and the warm air exhaled along the lower part of the nostrils. Continue to feel the breath and contemplate on the unity of the cosmic prana (inhalation) and individual prana (exhalation). Inhalation represents peace, infinity, fullness, transcendence. Exhalation represents spiritual freedom, expansion of consciousness, diffusion of the individual breath. Contemplate on these qualities for some time, feeling the breath.
Once the mind is absorbed in experiencing the prana inside the nostrils. Mentally and slowly repeat the mantra “Idam prana ayam atma Brahma.” Contemplate on the meaning—consciousness of prana awakens in me the consciousness of my atma, which is one with God—feeling the breath. Continue for several minutes, feeling the breath flow in the upper and lower nostrils while repeating the mantra.
Breathe freely, feeling relaxed for two minutes. Breath is slow and deep again. Inhaling, now move the mind upward and backward along the convex outline of a new moon in the middle of the head, the forward point being the nostrils and the backward point inside the back of the head. Exhaling, move the mind from the back upward and forward along the lower line of the convex moon. Feel the breath thus for several minutes.
Continuing, mentally repeat slowly the mantra “Idam prana sarva bhuteshu gudah,” for several minutes. Contemplate on the meaning—through the experience of prana I experience the spiritual essence, which is in all as it is within me. Continue to visualize the movement of prana along the convex moon.
Relax for a few minutes, breathing freely, with eyes closed. Breath is deep again. Feel only the inhalation, the sensation of prana moving up to the top of the head and the Sahasrara chakra, in the shape of the lower half of the moon. Give no attention to exhalation. Constantly maintain the sensation of the prana flowing up and into the crescent moon bowl at the Sahasrara chakra, renewing it every time by feeling the inhalation.
For the next several minutes mentally repeat the mantra, “Idam prana pragnanam iti Brahma,” feeling the prana inside the top of the head. Contemplate on the meaning —the experience of prana awakens in me the transcendental consciousness of God. Continue to visualize the movement of prana toward the Sahasrara chakra, being deposited into the crescent moon bowl.
Conclude the meditation with the verbal repetition of Om or the Purnamadah shanti mantra if you know it.