Om Namah Shivaya is at the heart on the Vedas and Tantras (ancient Scriptures) and finds its mention in the Yajurveda while in the Shri Rudram hymn. Perceived to be most productive if, while in the apply of Japa Yoga, wherever the mantra is repeated verbally or mentally 108 times https://youtube.com/shorts/CeBSHFfmcrE