and mystical meanings became an accepted practice, such as in the Tendai and Shingon schools of Japanese Buddhism. These Japanese practices included penance, austerities, ablutions under a waterfall, and rituals to purify oneself. Japanese records from the 12th century record stories of monks undertaking severe asceticism, while records suggest that 19th century Nichiren Buddhist monks woke up at midnight or 2:00 AM daily, and performed ascetic water purification rituals as a part of Tapas. Other practices include the extreme ascetic practices of eating only pine needles, resins, seeds and ultimately self-mummification, while alive, or Sokushinbutsu (miira) in Japan. Elsewhere, in mainstream Buddhism, over time the meaning of the word Tapas evolved, wherein ascetic penance was forsaken, and Tapas meant meditative and spiritual practices. The word Tapas appears extensively in Buddhist literature where, states Richard Gombrich, it does not mean "asceticism or mortification". The term Tapas means "meditation" or "reasoned moral self discipline" or both in Buddhism. According to Bailey and Mabbett, these Buddhist ideas are similar to those found in the Brahmanical (Vedic) tradition, wherein there is a great deal of overlap in the concepts of Tapas, Yoga, meditation and gnosis (knowledge), yet the term Tapas is rooted in the inner "mystic heat" themes of the Indian religions. Hinduism History The earliest mention of Tapas is in the Vedic texts. The concept of Tapas as symbolism for spiritual rebirth begins in the Vedas. Atharva Veda verse 11.5.3 compares the process of spiritual rebirth of a student in care of his or her teacher, with the gestation process during the biological birth of a baby in a mother's womb. Tapas is also found in the Upanishads. The Chāndogya Upaniṣad, for example, suggests that those who engage in ritualistic offerings to gods and priests will fail in their spiritual practice while those who engage in tapas and self-examination will succeed. The Śvetāśvatara Upaniṣad states that realization of self requires a search for truth and Tapas (meditation). Meditation and achievement of lucid knowledge is declared essential to self-realization in ancient scriptures. Texts by Adi Sankara suggests Tapas is important, but not sufficient for spiritual practice. Later Hindu scholars introduce a discussion of ‘false ascetic’, as one who go through the mechanics of tapas, without meditating on the nature of Brahman. Tapas is an element of spiritual path, state Indian texts. The concept is extensively mentioned in the Vedas, and the Upanishads. According to