Indus Valley seals
Several seals discovered at Indus Valley Civilization (c. 3300–1700 BC) sites depict figures in a yoga or meditation like posture. There is considerable evidence to support the idea that the images show "a form of ritual discipline, suggesting a precursor of yoga" according to archaeologist Gregory Possehl. He points to sixteen other specific "yogi glyptics" in the corpus of Mature Harappan artifacts as pointing to Harappan devotion to "ritual discipline and concentration." These images show that the yoga pose "may have been used by deities and humans alike." Possehl suggests that yoga goes back to the Indus Valley Civilization.
The most widely known of these images was named the "Pashupati seal" by its discoverer, John Marshall, who believed that it represented a "proto-Shiva" figure. Many modern authorities discount the idea that this "Pashupati" (Lord of Animals, Sanskrit pa?upati) represents a Shiva or Rudra figure. Gavin Flood also characterizes these views as "speculative", saying that it is not clear from the 'Pashupati' seal that the figure is seated in a yoga posture, or that the shape is intended to represent a human figure. Authorities who support the idea that the 'Pashupati' figure shows a figure in a yoga or meditation posture include Archaeologist Jonathan Mark Kenoyer, current Co-director of the Harappa Archaeological Research Project in Pakistan and Indologist Heinrich Zimmer.
In 2007, terracotta seals were discovered in the Cholistan Desert in Pakistan. Punjab University Archaeology Department Chairman Dr. Farzand Masih described one of the seals as similar to the previously discovered Mohenjodaro seals, with three pictographs on one side and a "yogi" on the other side.
See also: History of Yoga
Ascetic practices (tapas) are referenced in the Br?hma?as (900 BCE and 500 BCE), early commentaries on the vedas. In the Upanishads, an early reference to meditation is made in Brihadaranyaka Upanishad, one of the earliest Upanishads (approx. 900 BCE). The main textual sources for the evolving concept of Yoga are the middle Upanishads, (ca. 400 BCE), the Mahabharata (5th c. BCE) including the Bhagavad Gita (ca. 200 BCE), and the Yoga Sutras of Patanjali (200 BCE-300 CE).