The faiths born in the East — Hinduism, Buddhism, and Taoism — have long cultivated an appreciation for silence. They believe silence is essential to spiritual life. They see silence as a mark of spiritual maturity. The Chinese scripture called the Tao Te Ching says, "Those who know do not talk. Those who talk do not know." Those revered as the holiest people in the East — gurus, bhikkhus, and Zen Masters — are people of few words. They speak little because they believe, as Gandhi said, that "In the attitude of silence the soul finds the path in a clearer light, and what is elusive and deceptive resolves itself into crystal clearness." That's why Zen and other Eastern meditations are best practiced in total silence.
In Eastern religions silence is a prerequisite to spiritual purification and growth. Eastern religions teach that silence leads to inner awareness, wisdom, compassion, and loving kindness. Hindus and Buddhists believe silence is a way of achieving Moksha (freedom or salvation), nirvana (right-mindedness), or Buddhahood. In Theravada, silence helps a person to finally realize the ultimate goal — clarity of wisdom.
— J. Brent Bill, Holy Silence