Vishwanath chants during a Yoga Vidya satsang the mantra Om Namah Shivaya, which is a Panchakshara Mantra. You'll find it in the Yoga Vidya Kirtan Songbook as part of the Jaya Ganesha under the No. 2. Om Namah Shivaya is a greeting, which we use very often between or under Yoga friends. "Om" means Om, which includes all. "Namah" means "Greetings" and "Shivaya" means "to you, Shiva".