Om Namah Shivaya is at the heart on the Vedas and Tantras (historic Scriptures) and finds its mention while in the Yajurveda during the Shri Rudram hymn. Perceived being most efficient if, while in the exercise of Japa Yoga, in which the mantra is repeated verbally or mentally 108 instances https://willv851hkl1.thekatyblog.com/31430448/detailed-notes-on-10-most-powerful-mantra