the thoughts and intentions of the heart." Words which we write on paper are not alive and active. According to Scripture, the Word of God has existed since the beginning of the world, prior to any man-made language. Surat Shabd Yoga arose in India in the last several hundred years, specifically in the Sikh tradition (Nanakpanthi) founded by Guru Nanak. The practice of meditation (Shabad), which is the central core practice of Surat Shabd Yoga, is derived from the ancient Hindu practice of nāda yoga. Nada yoga is expounded in various Hindu scriptures such as the Nadabindu Upanishad, an ancient text affiliated with the several thousands-year-old Rig Veda. The practice of nāda yoga within Hinduism has been widely affiliated within many yoga traditions including bhakti or devotional yoga, kundalini and tantric yogas, laya yoga, and raja yoga. Modern Hindu teachers still emphasizing nada yoga include Swami Sivananda, Swami Rama, Rammurti Mishra (Shri Brahmananda Sarasvati), Paramahansa Yogananda (Kriya Yoga Lineage), and many others. The practice of nāda yoga is an integral part of various other traditions as well, such as being a form of the advanced thogal practice in the Tibetan Dzogchen lineage, and is mentioned by H. P. Blavatsky, founder of the Theosophical Society in her book "The Voice of the Silence". The form of Surat Shabd Yoga, practiced by followers of Sant Mat and the Sikh tradition (nanakpanthi), is most commonly related to nāda yoga. Furthermore, nāda yoga resembles and combines elements from the Hindu practices of raja yoga, laya yoga, and bhakti yoga. Movements and masters Adherents believe Surat Shabda Yoga has been expressed through the movements of many different masters. However, a basic principle of Surat Shabd Yoga's tradition is the requirement for an outer Living Master to initiate followers onto the Path. The movements whose historical Satgurus have died and their successors do not purport themselves to be Surat Shabd Yoga Satgurus, usually are not considered currently to be Surat Shabd Yoga movements, either by their own leaders or by movements with current Living Masters. Satguru Maharshi Mehi Paramahansa Ji Maharaj is considered the movement leader in the 20th century. He came to an isolated cave of Kuppaghat, Bhagalpur (Bihar, India) and practiced Surat-Shabda Yoga from March 1933 - November 1934. He achieved self-realization and attained ultimate salvation during his practice. He wrote books "Moksha-Darshan (Philosophy of Salvation), "Satsang-Yoga", "Shri Gita-Yoga Prakash", "Raamcharit Maanas Saar-Satik", "Maharshi-Mehi-Padaawali"